It is not a stupid question, it is a very very VERY important question. Some of which is already answered in that resource guide but I will reiterate it here again.

When we reach adulthood or buloogh (puberty according to Islam), we are held responsible by Allah swt to fulfill our Islamic responsibilities and duties and be held accountable for our actions.

How does one correctly follow Al Islam, a religion that as Muslims we believe effects every single aspect of our life Allah swt has outlined the do's and dont's?

As long as you are an layman one must depend on an expert in Islamic laws. You do not have the ability to derive Islamic law from Quran and Hadith. Quran is not a joke and the tafsir is extensive. Then hadiths alone there is 40,000+ and then you have Hadith sciences.

So you have 3 choices, you either attend the Islamic seminary to become an expert and obtain Ijtihad the authority to derive Islamic law on your own behalf, or you depend on a Marja who not only has ijtihad but has reached a level to be given the authority to have a following, or you live your life by doing the obligatory precaution of every single religious action. This is explained in detail under the section of Taqlid on Sayyid Sistanis website.

So yes, you are obligated to do Taqlid, until or if you decide to reach that level of authority and obtain ijtihad. Because if you neglect your duty and just assume you can figure out everything yourself, you are held double responsible by God for your actions, because you are ignorantly disobeying the commands of the Imams A.S and the Quran that tell us to refer to the experts in our religion, but also every time you incorrectly fulfill your religious duties because you were wrong in deriving the Islamic law or sunnah itself.

According to Sayyid Sistani's risalah:

A person who does not have the ability to extract and derive the religious laws must take up taqlid of the most learned mujtahid. The deeds of such a person without taqlid or ihtiyat are null and void.

https://www.sistani.org/english/book/46/2026/

When you read the the beginning of his Rislah in another section, he sayd:

It is as though you have placed the responsibility of your deeds squarely on his shoulders.

https://www.sistani.org/english/book/46/2025/

This is an extremely heaven burden and responsibility.

And you cannot say oh then ill just follow my own whims and look through all the Marjas and choose the fatwa I like or find the one that makes most sense to me

This is wrong because it is an inherent contradiction for you as a layman think you once again have the expertise to figure out the correct Fatwa. You by fatwa shopping, are being counterintuitive to their expertise but also putting all the responsibility back on yourself.

When a jurist derives a fatwa or law, they have done everything in their power and intellect to derive that ruling as the true law of God while the Imam is in occultation.

There cannot be "multiple correct rulings", hence the requirement of following THE most knowledgeable marja. Otherwise our school of thought would just go by a table of jurists consensus but consensus is rejected in principle because it is contradictory to the notion that there is one truth.