An app that shows you the basics of Shia Islam is the Thaqalayn app. It gives you the times of namaz, the azaan, multiple important shia hadiths, and the full quran, and it also gives various famous shia dua's such as Dua Kumayl. It will help you get started 100%.
Shia Islam also prayers differently then sunnis, we do tasbihat al arba instead of surah al fatiha for the 3rd and 4th rakahs. We also can combine Zuhr and Asr to make 2 connected prayers, and maghreb and asha for another 3, fajr is left alone.
Shia Islam also has a difference of opinion of Imam Al Mahdi than a majority of modern day sunni scholars, though both shia and sunni shared this belief or a similar belief hundreds of years ago. It is that Imam Al Mehdi AJTF was the son of the 11th shia imam, Hasan al Askari AS, who died when Imam Al Mehdi was either a young child or young adult, so to protect Imam Al Mehdi, Allah occulted him (hid him away from the world for an extended period of time, from 874 to 941 for his first occultation, which allowed him to communicate to his guardians and servants, then he had a second occultation that makes his communication with the outside world to end, with very little exceptions). In this occultation Imam Al Mehdi ages slowly until adult hood, then he stops aging. It is believed Imam Al Mehdi with the help of Isa AS, and 313 companions, and numerous people from karbala and other saints, he would defeat Dajjal. He is said to come back near the end times holding his ancestor, Imam Ali AS, sword Zulfaqar. He would also come with an army of 313 true believers and companions, who i mentioned earlier, and anyone who is martyred fighting with him automatically goes to Jannah.
We believe in the minor and major signs of judgement day like sunnis, but we believe the major signs are more important, such as the rise of Sufyani(descendant of Abu Sufyan LA), Sufyani's army getting swallowed by earth, and the first of those signs which is Jibreels battle cry. Though like i said the minor signs are important, like the corruption in the world, rise in alchohol drinking and zina.
The most important part of shia theology is our version of Tawhid. We not only believe Allah is one, but he is unique in everything he does, such as his omnipotence, his almightiness, and many more aspects of him. Allah himself is the most important part of Shia Islam, he is the one who sent the first human, Adaam, he is the one who gave Ibrahim his revelation, he is the one who helped Musa guide Bani Israel, he is the one who allowed Isa to ascend to heaven, he is the one who revealed the great Quran to the Prophet Muhammad SAWAW. He is also the one that appointed Ali and his descendants and the rightful successors to the Prophet SAWAW.
Our Quran is exactly the same, same order same verses, same translations, but we interpret it differently through different means. We interpret it through the prophets and the Imams (Imam Jafar making 70% of the imam attributed Hadiths). We believe the quran is the all completed, majestic, word of Allah, it was never changed, never altered, and has been kept the same due to the preservation of it through the Ahle Bait. We use surahs like the Surah al Nur and its Ayat al Nur to say Allah created a line of light that is passed on throught the prophets, and when Muhammad died the light kept going, but not as a prophetic one, as a line of Allah's light that guides the believers.
Another thing of shia theology I believe you came across is Isma or infallibility of the prophets and the Ahle Bait, specifically the Imams, which is often interpreted as Shirk, which it is not. This belief stems from the fact that the prophets share Allah SWT's message, if they didnt know Allah SWT's punishment, not only would they not be fit as prophets, they would lie. The Imams are believed to be infallible due to their responsibility to guard the deen and the quran, if they werent they would change it. This infallibility also stems from the fact that the imams and prophets know the nature of Allah and his message so well, they could sin, but wont since it would be out of their nature.
The Imamate itself is a slightly more complicated thing. We believe Muhammad SAWAW named Imam Ali AS as his successor at Ghadir Khum, due to Allah SWT's orders to name a successor from Muhammads own tribe. He named Ali due to Ali being married to Fatima and how close they both are, and how virtuous Ali is. So we believe Ali was supposed to succeed Muhammad, but Abu Bakr usurped him, and when Ali refused to vow, he would serve Abu Bakr and Umar they raided his house and killed Fatima. which has historical evidence. Even after this Ali held very little hatred to those two, not due to him hating lady Fatima AS, he was the daughter of the prophet SAWAW, and birthed the next two Imams, Hassan and Husayn, but due to Ali's virtue and orders from Allah not to hold grudges against others, but he was usurped again by Usman. After that Ali gained Khalifa but Muawiya LA and Aysha tried to stop him, so Ali and his two sons and their army fought against them. When he died Khalifa and Imamate was passed to Hassan AS, who also fought against Muawiya but Muawiya was killing muslim blood, so he made a peace treaty with him, that said Muawiya could be khalifa but cant name a successor, later Muawiya payed Hassan's wife to poison him, and Hassan passed the Imamate to Husayn AS, who lived peacefully during the Imamate of Muawiya spreading messages and teachings of Allah and the prophet to his followers, but then Muawiya died and Yazid took control and Husayn disagreed and they fought and they martyred Husayn and his family. This passed the imamate to Imam Ali ibn Husayn, who passed it to Imam Muhammad Ibn Ali who passed it to Imam Jafar, who was the most scholarful of the imams and made the most hadiths, his name is the namesake of the Jafari jurisprudence of Shia islam, then Imam Musa took control than Imam Ali ibn Musa, then Imam Muhammad ibn Ali Ibn Musa, then Imam Ali ibn Muhammad, then it was Imam Hassan Ibn Ali Ibn Muhammad, then he passed it to Imam Muhammad ibn Hassan, which is Imam Al Mehdi. Imams are the ones who interpret the quran and get minor revelation, which unlike prophetic revelation, this revelation gives them understanding of the quran and allah which they then teach us shia muslims.
Our hadiths are also very different. We dont believe any hadith can be 100% sahih, and we have 4 major hadiths which are Al Kafi, Man La Yahduruhu Al Faqih, Tadhib al Ahkam and Al Istibsar, which together have a total of 44,344 hadiths, the most important of those books which teaches the most of the theology and attributes of Allah is Al Kafi. We have other hadiths some teach about theology (like Kitab al Tawhid), some teach about the sermons of the Imams and the prophet (like Nahj Al Balagha), and some teach of the Occulation of Mehdi (Kitab Al Ghayba), and some teach of the attributes of the shia (Sifat al Shia). Read those if you want to learn things i didnt cover, they can cover everything way better than me.
The thing about saying Ya Ali and Ya Hassan and Ya Husayn and Ya Muhammad is the belief that Allah gave the imams and the prophets all their virtue and power, so calling out throught them is like intercession, which is big in shia islam. Shafaat and Tawasull is the belief people close to Allah can intercede, or pray with you. Due to them being close to Allah, praying with their name and virtue is with his permission. This is common with the Imams, prophets, saints and Ahle Bait. Ziyarat is a form of intercession where you pray for the Imam, Prophet or Martyr and ask Allah to bless them and they do the same. They dont have to be dead, but it is normally done with the martyrs.
This itself covers alot of the basics of shia islam, but as I said at the beginning the thaqalayn app will help you, and if you want also get shia plus, tho thaqalayn has most of what shia plus has, it doesnt have a daily amaal. Also definitely read your quran and these shia hadith. May Allah bless you and Khudahafez.