First ever guitar

I want to start my guitar playing journey on a National NRP tricone. I'd also consider a National S-1 or a Mule tricone. I must have listened to hundreds of guitars to arrive at this short list. Not interested in more budget resos or owning multiple guitars for different purposes.

My question is: how badly am I screwing myself as a student trying to learn on one of these instruments instead of a standard acoustic? Have any of you also learned reso first?

My goal is finger style and slide-heavy play, and I want to start learning slide asap so it's part of my journey as a student rather than something I have to go back and 'relearn' later down the road. With that in mind, what kind of fundamentals should I master before incorporating slide? Do any of you have advice on things I can do in terms of initial set up and strings to maximize my success?