Plz help a question about hair!?

i have curly frizzy , hair and i striahgten it and it looks great straight everyone i see loves my hair whn it is striaght and i was wondering is i was a) too young to get a relaxer ( im 12 ) b) how much does it damge your hair and is the dmage less that with a ceramic flat iron? c) is it worh the moey also how uch od they cost d ) how long do they normally last . e) anyone who has had it b4... what is a good way 2 take care of it after it has been done.. as far as the moisture factor and stuff like that ..