Christopher Schlegel of Guitar Tricks owns and uses a Katana 50. His opinion on anything to do with music, guitar and keyboard I value and respect. He sings its praises affording it a credibility absent in the endless fanboy cacophony.
That said, I don't have a Katana 50 original or Mk II, but they're loved by the majority of buyers who own one. I do have a similar digital modelling practice amp in an ID:Core 40. Any of a Katana, Mustang, ID:Core, Code et al would be a decent first all rounder choice as long as A. you are comfortable with the ergonomics and complexity of a digital modelling amp, and B. it's what you want. To effectively use the features of any digital modelling amp in general there's a considerable hands on learning curve, but their versatility will serve you well into the future so they're inarguably bang for the buck.
My own priority buying any guitar now having bought more than a few since I started is that personal physical fit is paramount, comfort in fretting its neck profile and fretboard characteristics being #1 priority. Second consideration would be based upon preferred pickup config and other design considerations i.e. scale length, string gauge, bridge type etc. Third, build quality overall, including an inclusive fourth of hardware.
What kind/genre of music is it your current future objective to hope to be able to play?
From the versatility standpoint, a HSS Strat style guitar is difficult to beat and has most genre bases covered. I'm personally partial to Teles too, but of course the conventional Tele config doesn't have a humbucker. Traditionally based Les Paul styles sound like a beast, but can also feel like riding one. Choice and thus info overload induced confusion abounds when starting out.
[br]Pick one you like the look of which feels good in the hand that doesn't cost an arm and a leg and dive in. It'll be an age before 'tone' becomes meaningful or practically matters beyond what an amp like the Katana can achieve with even decent if inexpensive pickups anyway.
[br][br]