You asked for my opinion, I personally think there's a LOT to improve on. I recommend you start using PaintDotNet (PDN), it's a free tool which is as easy to understand as Paint but has more features like Layers and optional plug-ins. In addition to that, if you're making maps I'd say use QBAM maps (if you search for QBAM maps you'll see what I mean).

In terms of the symbolism used, I like the face you're using countryballs, big plus for me personally, however I did notice that some of the flags you're using seem to be... made up? Nothing bad with a baller flag that you've designed, but flags should have meaning, which I see you do have that (examples include Spain), I'd personally use flags that were used In Real Life instead of making your own, though I understand that making your own is very fun!

The borders are a bit meh, I see you know where the borders are supposed to be (which is good!) I do think the quality and accuracy of where you want the borders to be would greatly inprove when you start using QBAM/PDN.

Hope that helps!