In need of help

Hi, I just got my kdx a couple weeks ago, been running fine and all, but just today, i was out and about to hop on the trails, when my bike stalled, started up again and kept stalling 3-4 times, so I said forget this, went down the rd, to go back home. going back and my bike stalls and my front brakes are smoking, could not get the bike in nuetral.When i was riding and shifting, the bike made like a grinding noise.Luckly a guy stopped, we put it in his truck and he gave me a ride home. got to my house and the bike was in nuetral , rolled it down in my driveway n put it on the stand. I have no idea whats going on with it, I picked it up for $400 as a beater bike and it worked fine until now :| , I just ordered some new clutch plates and a new shifter, which should be here by monday. What should I be looking for, and how do I drain the gas, Im new to bikes so I need your help. Thanks- adam