Tmobile plan question help please ? ?

I have had a iPhone using it like a iPodTouch due to not having service on it . it is jailbroken and unlocked & when my att service ends in a month I'm thinking about going to globule . When I buy my cell phone on the family 1000min + text plan no data if I put my sim in the iphone I have will they charge me data if I don't have the Internet settings for tmobile ? will I get any charges . Also all I'll be putting in on the settings is the mms settings . Not the Internet I would like to know jus if I would get any other charges or anything ?