u/DepartmentNo1220

I have never flown with AA and have a flight coming up in a few days. After I purchased my tickets I noticed it said I would be in group 9,which im assuming is last, I dont mind since its basic economy and I expected that. I read somewhere that if you are AA rewards member or whatever its called that u will board in group #6. Is this true? Just trying to prepare if I will have to check my bags and if so how will i know there is no room if i need to check my bag?or if there will be room to store my carry on.