I would echo the Joan Bailey book recommendation. She also wrote another book for older dogs “How to Have the best trained gun dog”, also recommend.
Neither of her books were written when ecollars were widely used. For good info on using ecollars (and general dog training), Craig Doherty’s book “Building a grouse dog” is good.
Group training days are good, but not all the groups or people in them are that good or might have very particular ideas that don’t necessarily make sense for you and your dog. So take advantage of these but if something seems off, do your own thing or find another group.
You mention that you have some more time now for a dog. If that’s the case, I’d recommend doing whatever you can to basically live somewhere with wild birds for as long as you can during your dog’s first season (and for that matter, all of them, lol). I was very underemployed during the fall of 2020 and moved to the grouse woods with my 6m old puppy that fall. We hunted every day. Before we went, he had a very solid program of gunfire introduction, would come when called and was used to off leash walks. He had a little planted bird exposure (that in retrospect probably wasn’t that necessary). But he basically taught himself how to hunt on woodcock and grouse and developed into a very enthusiastic bird dog up there. He seems to have more desire than a lot of dogs I’ve met on training days - perhaps that is just innate or maybe it has something to do with that first season. He was still a puppy of course and made all sorts of puppy mistakes, but I feel that fall really laid a good foundation for him.