I plan on goin for the nba what should i do?

ok so here the story is, my mom is a very college oriented mother and i dont blame her. however i want to be an nba ball player. personally i think that i should go to a good enough basketball college and go for the four years. is it possible for me to graduate college and then enter the draft. or could i enter the draft in my senior year at college. if u dnt get accepted can u go back. i herd u cant if u sign an agent but what does tht agent do. eve nif i dnt get drafted i plan on playin d league and hopefully get signed. how much do d league players make. how much does all this nba draft stuff cost?