Sure, you can ask me stuff. I'm not really the best at giving advice, but I'll try to answer what I can.
As for stuff to keep in mind, I'm not sure how much travel you're used to doing, but once you have a gym, you're expected to be available there pretty regularly, so it's still doable, but something that you'll want to plan in advance a bit more. Knowing some of the stuff that happens here sometimes, though, you might want to consider what you want to happen if you get whisked halfway across the continent and can't get back right away. Especially if you want to open your gym to more than just battles, or if you have any set ups that need daily maintenance.
The response comes... not as late as this (oops) but still after a couple hours or so
As for stuff to keep in mind, I'm not sure how much travel you're used to doing, but once you have a gym, you're expected to be available there pretty regularly, so it's still doable, but something that you'll want to plan in advance a bit more. Knowing some of the stuff that happens here sometimes, though, you might want to consider what you want to happen if you get whisked halfway across the continent and can't get back right away. Especially if you want to open your gym to more than just battles, or if you have any set ups that need daily maintenance.