Ni Highthawk99
I wouldn't get too bogged down in the theory - it is very helpful in the long run, but not if it comes at the expense of enjoying playing

3 chord tricks (1, 4, 5) are the basis of most country music and will serve you very well. Add a 6 minor and 2 major to the mix and you won't run out of stuff you can play on the lap steel!
From personal experience, I would suggest if you're learning lap steel, the focus should probably be more biased towards the physiological side of learning, i.e. muscle memory and controlling tuning, vibrato, string damping, bar slants, etc. For me this was the big challenge (and still is!) - the theory side kind of falls into place gradually the more you play. It will come in fits and starts - I wouldn't force it!
Sounds like you have a great tutor, and if you're seeing progress then everything is great. I find it really helpful (though cringeworthy at times) to video myself playing a particular piece so I have something to refer to, to gauge my improvement. You may be surprised how much better you get over time

I recently attempted to learn a Brent Mason guitar solo and play it on my acoustic guitar, and videoed my attempts. After 2 weeks of practising most nights I got it up to about 80% of the target speed:
My point is that you will be a lot more motivated if you can see how far you've come, and videoing yourself really does help with that.
Good luck with the lessons - lap steel is a fantastic instrument and it's great to see so many people on here playing it!
Cheers,
Simon 'Sid' Farley