What happens when you belly button pierced what can happen to it like infection?

All professional body piercing studios provide clients with written aftercare instructions, some provide detailed instructions for specific piercings. If you are looking for a studio this should be on your list of questions before you decide to get the piercing done. If they don't provide instructions inwriting you are in the wrong place.

Also don't get talked into buying all sort of aftercare products, piercing studios can only recommend an aftercare product, you are not forced to purchase it, if you are that is illegal under consumer protection laws. Besides that it would also be illegal under medical regulations it's call "prescribing" and that can only be done by a licensed medical doctor.

Ultimately cleaning a piercing is like taking care of a cut except for the fact this is a puncture wound. Using diluted liquid antibacterial soap and washing the piercing when in the shower, then flushing the piercing with plenty of running water while moving the jewellery should be plenty. Doing this daily will help the piercing heal and keep it healthy, you don't need lotions. potion, slaves, balms, sprays or soaks of any kind just good old antibacterial soap diluted and water...that's it.