National Forest access roads if not too rough can lead to some wonderful camping locations. Google maps satellite view of NF land can be useful way to find roads that lead to remote locations, and the location of places to turn around.
There are fire, waste, and trash disposal rules for NF lands but no amenities. And generally not much in the way of humans either.
You can dump a porta pottie at a vault toilet, flush toilet, or campground dump station. Just be sure you are responsible for your mess. Best not to make one if you get my drift.
Some of those little changing tents come with mesh or detachable floors for use as a shower but many are not
able to handle the weight
of a solar shower bag being hung from them. Me I just heat a coffee pot of hot water, have canteen or two of cold water, mix in small dish pan and dump on self with a plastic mug. All items that I take with me when camping anyway.
Some people consider all camping without hook-ups to be boon dock camping, others sort of differentiate between rustic campgrounds (vault toilet, water, fire ring) and camping in dispersed locations in the woods or desert.
Rustic might offer an easier place to get started. Let you do as Diane suggests, try it and find what works for you while still having some facilities available.
I would also suggest giving some thought to first aid if your going to head out to camp in the middle of the national forest lands. Not a big fan of the off the shelf first aid kits, suggest getting a book on back country first aid, reading it, then accumulate the items it suggests. By purchasing and putting your kit together based on first aid need each item addresses you will be mentally prepared to use the kit. Blood spurting from a severed vein or artery from a slip with an axe is not a good time to flip open the store bought kit and instructions to figure out what to do.
When your 10 miles from a paved road in the wilderness the solitude and experience can be wonderful, the 911 response time once you get to cell coverage not so wonderful.