Ear piercing question?

Hi i am 22 boy, about to pierce my both ears this week, i have no idea how it feels but i like to do that.after getting it done when i can change my earings? what are the chances of side effects? and i don't like to wear studs my girlfriend and i both like hoops only.she wants me to put on one on each small silver 14mm dia. 2mm thick bar hoop earings? from where i can buy such hoop eaings, please give me idea about this..answer please.