Photoshop is one of the most widely used, professional, and capable
tools for mapmaking you can find. Sure, I don't think it was designed
with mapmaking in mind, but a lot of cartographers here in the guild
have been able to master it with amazing results.

I have MS Paint, so I'm able to understand that's a more basic tool.
But, being a more basic tool, it's easier to learn and beginners
shouldn't have as much trouble getting to know it. I don't have
photoshop, but if I did, I probably would know how to get started with
it.

I like the border of your map. It reminds me of a simple map that might
be used for nautical navigation or such. You did a fairly good job avoiding
the square look, but I don't think the pixelation helps that.