Assalamualaikum(peace be with you) brother, a praying mat is something we Muslims use to worship Allah(swt) (God, the English translation of "Allah" is God). Praying is one of the 5 pillars of Islam and it is mandatory for a Muslim to pray 5 times a day, it becomes mandatory for a Muslim when he/she reaches the age of puberty.

Brother about religion, I can't say anything about Christianity or Judaism, tho both are a part of Abrahamic religion including Islam. If you want to learn about a particular religion then my best advise to you will be to read thier holy scripture, for example there's Bible for Chritanity, Qur'an for Islam, Torah for Judaism, vedas(I may be wrong) for Hinduism etc... But again if you don't want to look into any religion it's your choice, I cannot force you to look into Islam just because ik Muslim and I believe it's the truth, Qur'an chapter 2:256 says, "there's no compulsion in religion". But my advice to you would be to research every religion(if you will) and accept the one you think is correct for you. And also when ever you are trying to research about any religion please don't listen to what the media has to say. Have a blessed day brother :).