Question about church?

im new to being a christian and im so confused about how i know which church is the right one for me i dont want to go to one against gods teachings.keep in mind im new to being a christian. why do some churches think you have to be baptized and you have to speak in tounges to be saved why do they believe this ? if it says it must be done in the bible i will do it but i have to know for sure its right. are we still under the law keep the sabbath day holy? if so does that mean if i dont go to church on sat. im sinning? and if its not required please explain why its not because from the little bit of the new test i read it is so please explain ur answer im wanting to go to church on sunday if poss