As said above, you will need an INverter to convert 12 volts dc to 120 volts ac. It takes a lot of battery to invert to large load appliances like a micro wave. Smaller 120 volt items like a television, laptop etc can be powered with much smaller INverters. It's all about putting together YOUR energy management plan. There is not one answer for all rvers. In short if you want to spend the least money and effort for limited camping you are probably better off to use a small generator to power the heavy loads. If you want to make life easy on yourself and not be considered a jerk, you will want to buy a quiet generator.
After that, if you want the ability to stay off grid longer on your general 12 volt items you may need to up grade the amount of battery capacity on hand. For example if your rig came with a group 24 marine/rv battery it is the smallest size available. Group 27, 29 and 31 go up in capacity. If a gp battery has 85 amp hour capacity only about half of a batteries amp rating is available for you to use or it will be too deeply discharged. When you use your 12 volt items they are pulling amps from the battery. Each item requires X amount of amp draw. If an item uses 2 amps and you run it for one hour you have used 2 Amp Hours out of your battery. If you ran that item for 20 hours it would use about 40 AH. It's common for an rv using it's propane frig to use about one or more amps to just sit there without turning on any other items. This means that an rv could discharge one group battery in a couple days. If you then start using lights, pump, tv, fans etc it could easily use that battery in one day. Some people who camp for a weekend could increase the battery bank and recharge when they get home.
If the same person wants to stay out and boondock they now need an efficient means of charging the battery. RV factory converters often dont provide the quicker charging that is needed when using the rigs CONverter and a generator. It common to replace the CONverter with a unit of higher charge voltage and sometimes higher amperage depending on how many batteries you have added.
LED bulbs are a good upgrade. Choosing a generator is divided into two basic sizes. If you ever want to run the AC it will usually require a somewhat larger model or you can sometimes modify the ac unit to be able to run on about a 2000 gen. 2000 watt is probably the most popular size. There is a lot of reading on here about that issue.
