Hi Elis,
I have had my ears pierced twice, one time at a shopping mall using a piercing gun, and once by my girlfriend using the sterile cartridge they use in the store. It doesn't hurt much and is over in less than a minute. As others have said, just keep the piercings clean - they supply you with antibacterial wash at the place I went - and move the studs daily by rotating them or pushing them up and down. That usually happens when I clean them anyway. Once they have been in about six weeks, you can take the piercing studs out and put in whatever you want.
Hope that helps,
Terri