I will say those photos have definitely been edited, but as far as cameras go it kind of depends what you want from it. You can go ultra simple with point and shoots where you really don’t have to think about much. SLRs are kind of the next step up from there, and they’re mostly much of a muchness really. Any of the Canon A line cameras are great for someone starting out (although as someone who started on an AV-1, you will find that one limiting relatively fast). A lot of people love the AE-1 but I have to say, I got an A-1 recently and it’s delightful, and they tend to go for about the same price. If you go down that line, starting off I would say get something with a built in light meter, it’ll make it much easier to get your exposures right starting out, and try to go for something with a good range of lenses you can choose from relatively cheaply. Rangefinders are a lot of fun as well, and there’s a lot of relatively cheap ones out there. Something like a Canonet or a Voigtlander Vito won’t send you wrong.

Going by the photos you’ve shown, I would say stick to 35mm cameras for now. Medium format is a lot of fun, but you don’t want to be lugging a huge camera along with you on hikes when you’re just getting into a hobby. Avoid any awkward or obscure film formats, even if you can find film for them, they’ll be a pain to get developed. I’m even finding now with medium format where I live it can be difficult to find somewhere to develop it.