2oldman provided a link to the 12V side of life. You should definitely read that. It will tell you what you can and cannot do with battery power.
Battery power is very limited and, as a rule of thumb, you cannot run much of anything that generates heat (like your 3 way refrigerator or microwave) off of an inverter unless you have huge battery bank - probably 5 or 6 100 Amp-hour batteries.
The lack of a bathroom and a black water tank is not much of a problem if you are at most campgrounds - they provide toilet and shower facilities at centralized locations as well as 110 V hookups at each site. However, you should be aware that disposing gray water on the ground is generally illegal.