I tried gimp, and still use it sometimes, but switched to affinity photo mostly because the smart select tool was so much better, and the Ux was a lot smoother. Faster too. They are basically the same program in a lot of ways and if I’m on Linux (I dual boot) I do use gimp sometimes still. You will spend some time on YouTube trying to figure out how to do things but there are a lot of good short videos to get you moving

On a related note, I used kdenlive (video editing) the other day and it was a really good experience, smoother and faster than a paid editor I used to use