Since you are talking about wilderness camping, and presupposing that everyone should be following Leave No Trace, camping skills can be practiced in many places - even on public camping grounds to some extent.
If you take Leave No Trace seriously, and actually try to minimise your footprint on the area you visit this will mean...
- that you cook on portable stoves using fuel which you brought along - instead of collecting/cutting wood for a fire,
- bring with you all the food you plan to eat - instead of foraging/hunting/fishing,
- you rely on tents/tarps - instead of constructing survival shelters
- you'll carry out all of your waste, including excrement (or at least the harder-to-decompose parts, such as toilet paper),
If this is what you are looking for then I suggest to get some first experience doing some test runs on public camping grounds. Since your impact on the environment should be minimal and you are in essence almost completely self-sufficient there is no real need for any wilderness - apart from the "being alone and undisturbed" part.
Once you're comfortable with your gear and your setup you could go for longer overnight treks. There are plenty of areas where you can enjoy remote outdoor experiences - Norway, Finnland, Sweden, Scotland come to mind where you will find wilderness areas that are
- remote and "wild",
- still accessible for camping and trekking,
- there is a public right to camp (I suggest you look into this some more, or specifically ask a question here about a region you are planning to visit).
A personal recommendation would be to look into the Swedish trekking route "Kungsleden", as a starting point on Google. IMHO it offers a good combination of wilderness and accessibility, with many options to plan routes into even wilder / more remote / more solitary areas.
From your questions it could also be that what you might be after instead is a place where you can go and try out all the cool bushcraft and survival techniques that many YouTube channels so generously supply us with... If that is the case I'd like to state: many of the shown techniques don't generally go too well with Leave No Trace.
--> Building tools and improvised shelters from trees and deadwood, cooking on open fires, collecting food / hunting animals and generally camping in the same spot for a longer time (say, multiple days) will leave a significantly larger footprint on the area you are visiting.
This isn't to say that there aren't some rare and valid applications for these techniques - but if you are looking for official regulation condoning such techniques you will be hard-pressed, since the prevailing trend is going towards Leave No Trace (and for good reason, I might add), and all the bushcraft/survival hullabaloo is in conflict with this to at least some degree.