I've only ever heard good things about Yusupov's books. They shouldn't be out of your league because his books are organized by strength and are designed to give you a complete understanding from the ground up.
As for tournament play. Don't worry about getting dismantled. It will happen, regardless of when you start playing or how ready you think you are or are not. That's part of the OTB journey. If you keep procrastinating getting out there and trying, you'll only be stunting your growth long term.
Not being someone to miss out on a bargain I came across the full set of 9 books by Yusupov in a charity shop for a mental price of only 20 quid. Admitedly I hadn't done any readin up on the series, but the 9 book set for that price was a pretty decent deal (they are also in good nick and the hardback versions)
I haven't really read any chess books so I will be honest ,this was pretty much an impulse purchase because of the price. I am currently rated just under 1000, played a lot of chess all through my early years, was on school chess team and then had something like a 25 year+ hiatus. Joined chess.com during lock down, played for a few months then got side tracked with work and have only just recently come back to playing again.
I mostly play on a chess computer (have chesssnut Evo, got mainly because of the analytics and game review which helps me work out where my weaknesses are, plus i like playing OTB rather than on a PC) and enter a few tournaments on this site. However I am constantly worried about getting quickly dismantled which kind of makes me hesitate on entering more of the tournaments.
For someone like me who is only an average player that has a decent graps of the fundamentals and looking to get to the next level are these books worth the time investment ? or are they still out of my league and I should look elsewhere before taking this series on ?
thanks