Please tell me how to care for my belly button post op.

By 7 days after the surgery the tapes should be off.  It would require nothing more than normal showering and keeping the area clean and dry.

I recommend calling your plastic surgeon's office for directions. For my patients, I have them clean with dilute peroxide with water then use antibiotic ointment. After drains are removed they can clean in the shower with doap and water.

Your plastic surgeons office should be able to give you verbal instructions over the phone and I highly recommend you call them for their protocol. In my office I have the patients apply antibiotic ointment to the belly button daily and cover with gauze for the first 3 weeks.