Hi there, and welcome to the Guild!
I originally started with Photoshop Elements, and while it was mostly okay at the beginning, I eventually did outgrow it and couldn't even imagine going back to it now. I was working with Elements 9 back then, and at least at that time it had some major disadvantages - the most damning one being the complete lack of the Pen tool and thus free-hand vector path capabilities, in addition to it being unable to work with CMYK colors - compared to full PS versions. Not sure what the most current version has, though. After moving on from Photoshop I did work several years with Photoshop CS2, and it served my needs extremely well, so even a very old version of the full PS ended up being better than Elements.
If you are looking for more realistic maps rather than the antique/hand-drawn style, this tutorial is one of the best examples of what the full PS, even a pretty ancient one, can do for you. Also, this and this include some extremely useful tips and ideas for the kinds of style you seem to be after. I personally tend to use techniques that are a combination of all three with my own twist on them.
All that being said, you most likely can get started with Elements too, and maybe it would be a better idea to try things out before you invest in the full PS. Especially since I'm pretty certain Adobe doesn't even sell the CS6 package anymore, and you most likely would have to get the CC version anyway, that can be a strain on one's wallet. There are also several users here who have produced some pretty darn impressive maps with Gimp and other free software (check this one out, for example). I also personally will offer a careful recommendation to checking out Affinity Photo, that is a semi-recent addition to the world of photoediting software and has gotten a lot of praise for being a serious contender to Photoshop. It's also incredibly cheap compared to PS. I haven't really worked with the AfPhoto yet, but I do own the Affinity Designer vector design software and already prefer it to Adobe Illustrator, so at least I can say they seem to know what they are doing... But as I said, I haven't gotten around to actually trying the AP our for myself yet, so I can only recommend maybe giving it a look, as I can't say if it's worth it or not.
In conclusion, there are many ways to produce a map. But in general, I absolutely can vouch for Photoshop and myself ended up thinking that PS-E was not enough for me after a while.