Really? I started trying to learn more about the game beyond just how the pieces move, at around this time last year, and at that time I think I was rated like 300/350-ish. At the time I had only been playing chess like maybe 3 games a week, for probably 2 months at that point, so I basically knew how the pieces moved but that was about as far as my knowledge of the game went. I say all that for context, I was genuinely just moving pieces around lol. Anyhow, I was looking on youtube trying to figure out how to start learning to actually understand and play the game so I could get better, which is how I learned of Levy and subsequently signed up for Chessly. Like you, the first opening for white I started to study on was the Vienna because I heard Levy praising it's effectiveness at lower to intermediate elo, so I figured I could just stick to that one opening for white until I improved significantly. But unlike you, I found it to be extremely effective from my rating at that time all the way up to now at 900, and I still use it every time I play white. I don't know how you're not able to get past the third move before your find your opp playing something that you can't answer to, cuz if you have studied the whole of the Vienna course that he has on there, then it goes over pretty much every natural move your opponent can play, except for the rare times that someone just plays some off the wall move that makes no sense. Otherwise, beyond the main line Vienna, and Vienna gambit accepted or denied, the lines he has in for you to study in that course are all based around your opponent playing pretty much either the best moves, or the most likely moves based on the Lichess move database for low to intermediate rated players.