[Build Help] First time builder need help budget $630-780

Hey there so i have to decide to spent my money on buiding a new computer but not really sure what parts to get my budget is $630-780 i already have a hard drive and optic drive all i need is the other parts. I will mainly be useing for gameing and other thinks which require alot of cpu useage so plz recomend your parts below. Thank you all for the help :)