Abscess on shoulder. went to er got antibiotics and told to let it drain. we took the bandage off and now there is a whole there is this normal?

Sounds ok: If one has a skin abscess, and it opens up, it should heal from the bottom up. That means a hole is a good thing, because junk can drain out. If it seals itself, or if the hole is too small, the junk will build-up inside (that's bad). The inside cavity (may be seen looking through the hole) should get smaller each day. One should recheck with the doctor if the area doesn't look better each day.