Yes, paint. net is a very good application. While there may be some things that it does not have compared to say, Photoshop, it does also have some things that other applications don’t have themselves (If I do remember correctly).
It may take a small bit to get used to, as from what I know of it isn’t as frequently updated and improved as much as some other applications may be, so it may be a bit tricky at first. Though from just messing around with it you can get a good understanding of how it’s used. The layers feature was one that I kept getting messed up on, though eventually I managed to get it.
It may not be super quick, learning and understanding it, but once you do you can create some pretty cool things.
Like for example, this thing I made here:
It’s not yet complete, but it’s of an anime, a custom background I’m creating. I took a screenshot of part of the intro sequence, it wasn’t very high quality but I was still able to make it look pretty good, I probably wouldn’t have been able to do what I did so if I had used something else, or at least it probably would’ve taken me a lot longer, though that’s just me.
The application does provide some really useful easy to use tools though, I realize it may be difficult to learn how to use them but compared to some of the applications like PhotoShop, it can be a lot easier to learn.