The best way to find out what you want/need is to do sever short (2-3
day) trips close by a Wal-Mart.  When you need/want something, make a
list and go shopping.  Big Lots often has camping gear cheap.

After a few of these "Shake Down" cruises, you will build your own
essentials list.

Talking to other campers in the camp grounds is another way to get a
good rig set up.