I bought a SeaSkin, and often recommend it to others. It is the best value suit on the market, but you're right, it will take a few months. To my mind, a few months is better than a few thousand dollars, but you may not agree
My suit arrived in the early months of the covid pandemic, so no courses were being taught at the time. I just taught myself, it's really not rocket science. You need to understand how the suit actually works, how to don and doff it, and to get used to keeping a minimal amount of air inside the suit
The easiest way to manage the air in the suit is to just leave the valve open whenever you are underwater, and when you feel it getting kinda stiff on descent, add a few squirts of air in there. Just like managing your BC air bubble, the differences feel bigger in shallow water than in deep water. If you get cold, you need more air inside the suit, but not in the form of squirting a bunch more air in there. Rather, in the form of wearing more / thicker underclothing on your next dive. A good hood and drygloves also go a long way toward keeping you warm. Best of luck
Edit: oh, and if you are a person with male junk, just go ahead and get a P valve, you will want one some day or another. All of the alternatives are pretty unappealing. For folks with female junk, a P valve is a little more involved... I can't speak to it from firsthand experience, but I can see why some folks would prefer an alternative. But if you can pee standing up, a P valve is the way to go