Planning my shop Build-out for next summer, looking for advice.

I just responded to this thread regarding winterization, and it got me thinking:

https://www.forabodiesonly.com/mopa...-classics-for-winter-hibernation-sigh.570260/
I've always only had a garage, and never a Shop, per se, and this metal building was one of several reasons we bought the new place a couple years ago. Here's a picture from when we were moving-in:

IMG_5235.JPG

Building measures 24' x 42' with a 10' ceiling, has 100 amp service, and the wall posts are 7' on-center. I'm planning on building the walls "sideways" (7' tall w/either 18" or 24" centers, laid-down sideways) so that I can utilize readily available R-25 insulation), and I already have a furnace and A/C for it. Floor is already in, and because I don't know the thickness, and don't want to drill (plus I don't have much height to work with), a lift of any sort is out of the question, sad to say.

I have all winter to think about what I'd like to do with this space, and I do have some ideas (such as adding windows, and getting rid of that back OH door), but I'm also smart enough to know what I don't know, so I'm looking for advice from those who have "Been There & Done That". What should I be thinking about, and what mistakes should I avoid?

Thanks, all!

Jim