Welcome to CB! If the Pearl is either an At&t phone or unlocked then yes. Carriers lock devices to only work with their network. They can be unlocked to work on all GSM networks with a code you can get from the carrier or third party unlocking services.
As for the internet...
If you want to receive E-mails you are going to have to get a data plan from your carrier. That automatically gives you internet.
If not and you just want to use SMS (text) and MMS (pic/video) then you don't need a data plan and therefore won't receive internet nor will you receive E-mails.