BartK The Amy Protscher videos I linked may not be right for you. They assume you have a little proficiency at jazz.
I know what you mean about jazz feeling like a mountain. I had been playing classical for 15 years before I started jazz, and it was so frustrating to feel like almost everything I learned about piano was useless. I could play make beautiful music with Chopin sheet music in front of me, but take that away and I couldn't even make a simple melody sound good. The good news is all of that classical experience does help with jazz, eventually. But for the first two years, it really is like learning piano all over again.
Pallas, on that note, if you want to start learning how to use a fake book, I think earlier is better than later. Pop songs are a great way to get into it!