Hi Tekodal and welcome to the Guild.
About uploading images, it looks like you've done everything correctly, though you could probably have made your image a little larger. There's info on the file sizes you can upload
in this comment.
About the map itself, a couple of points of constructive criticism...
It's hard to see details due to the small size of the image, but it looks like you have a couple of lakes without any outflow. This is pretty rare (so I understand). You might want to take a read through our '
How to get your rivers in the right place' thread, which goes into a lot of detail on this topic.
I have to admit I'm not too keen on your labelling. Labels should always be clear and legible, and unfortunately yours are not. Take a look at the black label on the forest at the top. I can't read what that says because of the dark background. The white label over the island at the south is also hard to read.
Some suggestions...
Add a border and a title to the map. You have a lot of empty space around the edges, and a border and title would fill that nicely. A nice decorative font for the map title would look good, but perhaps something plainer might be better for the geographical labels (and probably smaller labels would be better too - you don't need to fill the entire area). If you're looking for some homework on best practices for labelling, take a look at
the PDF in this comment. You don't need to read and memorise every bit of it, but have a scan through the first few pages particularly, to give you an idea of what to aim for.
Now with that out of the way, you're off to a great start and you've got the basics of a good map down. I like the colours you've used, and I love that grungy background! However, I do feel a few tweaks would make it so much better.
If you'd like to work on this some more, I can move this thread to the Work-In-Progress area, and you can get some feedback as you work on it. But if you're content to leave it as it is, that's OK too.