Good morning,

For me it's important not to stagnate but not to be going forward so quickly that I am not really learning the lesson material - be it chords, scales, licks, songs etc.

I get a good handle on a given lesson and then revisit. Some stuff comes easy, some not so much. I think you need to work out for yourself what is the right time to move on. In the end, you want to be able to play "something", so if you find yourself in a state where you have lots of lesson history and time in learning - but still can't play anything - be it a song, a chord progression, scales etc - you have moved ahead too fast.

Good luck with your studies.