Newbie Electrical Issue - Advice Needed Please

Try using the genny with some breakers turned off,
Run just the AC and check load, then after a while add items, you should see when it is having a large addition and then be able to tell what combination of appliances is causing the overload.
As others have said Water heater, and fridge running on 120 volt ac when AC is on is my guess, in which case for camping, use propane for those items unless you are somewhere with a good 30 amp connection.