My first begonia

Hi everyone! I got my first begonia on Saturday for a cool $6 and I’m completely in love. Unfortunately I think it might have been unhappy in the greenhouse where I got it (it was -20 C outside all weekend). I gave it a bit of a haircut and staked it for support, but I’m wondering if these markings on the leaves are something I should be worried about. It’s in quarantine right now and I’ve been giving it the grow light the last few days cause there’s no other way to light it in the quarantine zone. am I being paranoid or is this lil buddy gonna be okay? Any other tips or things I should be aware of?

photo 1 is from the day I got it, photo 2 is the plant post haircut / with stakes, and photos 3 and 4 show the little bit of damage I’m fussing over (sorry, I’m a new plant parent haha)