Important question? need help ?

hi guys just wanna know something simple. i am 26 yrs old and 5.5 tennis player and wanna start playing tennis professionally can some tell me how to start. there are lots of site giving information about how to became a pro tennis player but no one give simple answers i just wanna know what i join first USTA, ITF OR WHAT to start playing some matches and is there any requirements for entering small tournament. and what si futures tournament and Satellite tournaments can anyone play or what someone have to do to play in small tournaments and don't have any ranking or points PLZ TELL ME WHAT DO REALLY APPRECIATE A GOOD ANSWER??