Also need to know the physical space you have available for batteries. That will tell us what battery configurations you have room for.
So, you need to add up all your electrical needs, find a battery(s) that meet hose needs (generally provide overnight power)without discharging below 50%.
If the batteries are inside the RV, look closely at AGM batteries such as Lifeline, as they don't outgas except under extreme overcharging.
More facts, better answers.