2002 Yukon P-O-S

What is your question?

I bought a 2002 Yukon Denali 3 months ago and we are experiencing problems with it. The service ride control light stays on, while i'm driving there is a rattling in my back right (pass.) tire, when it's either hot outside or i drive on the freeway for a while the front drivers tire makes noise when i make turns (i'm not over turning either) also when i change gears there is a beeping sound please help i don't know much about cars just that i got screwed when i bought this one.