Engine Bang smoke

ok where do i start ok first of all my battery was dead so i boosted it then i went to try and start it turned over once and BANG and a big cloud of smoke came out around the air intake and burnned a hole in the air filter hose and smoking so now i am afraid to mess with it and dont know what it is? anyone have any idea what it could be? the engine fried? or back fire or what someone please help!!!