Want to get into nature/mountain photography.

I'm big into hiking, climbing mountains, backpacking, etc and has always found photography interesting and wanted to give it a try. I don't know much about photography and am looking for advice on what I should research and/or any camera suggestions. I'd be looking for a portable setup (because I would be hiking with it) and would primarily be photographing mountains, nature, and if possible astrophotography - however I would assume that that would require a very different setup. I've heard that buying second hand for your first setup is a good idea in case you don't end up enjoying photography, so I am open to that. Looking for something that won't break the bank but can also last be awhile if I end up sticking with it. Top end of the budget would be around 700CAD (500USD).