Hello Tigro,
The JustinGuitar Rock Songbook has a lot to offer. The challenge that a few of us started is to play and perform every songs in the book with a backing track. The songs in this book are more complicated than the beginner songbook, so they offer plenty of challenges.
Most of the first 15 songs are about the level of grade 3 and some are grade 4.
Then the next 15 songs are intermediate with a lot of barre chords and complex rhythms. And after that advanced… So you gradually grow a lot while doing it. But, it’s definitely achievable as you take it one step at a time.
Here is an example of my version of the project which have the first 10 songs of 15. It’s a really practical project, I learned a lot while doing it and I’d recommend it over another course.