You would need to check with your inurance plan to see if Celebration is a "provider" for them. (Or, call Celebration and see ask them if they are a provider for your insurance. Listen carefully to their wording, since some clinics, hospitals, etc will say they will bill your insuarnce, but if they are not a provider for your particular plan, there could be heavy out of pockets expenses you will be responsible for.) HTH
Most "public" hospitals will take you regardless, you will just have to foot the entire bill, but most will send bill to you, if they don't take your insurance.
Many "walk in clinics" are much more picky on insurance, so you will need to pay while there. You could try to file a claim yourself, again depending on your insurance. Mine does not pay walk in clinics.
But this is just my experience in S. Florida clinics/hospitals.
The walk in's don't take insurance its cash/credit card. If you get authorization from your doctor to go to the hospital you insurance will pay. If it is an emergency (chestpain, car accident) and you go to the hospital you need to notify your insurance withing 24 hours (usually)