If you are using Gnome stay with that first. You can try gnome extensions and gtk themes, there are lots of possibilities. Many of the things that people post for other window managers will not work on Gnome.

Then know your command line well https://github.com/jlevy/the-art-of-command-line

Then try to automate things, such that e.g. you can open a QR code of your clipboard with a key binding. Or whatever cool things you want your computer to do.

If you like these things and you have a lot of time, try other window managers as well. Start with something that has a good example config and good resources online, I believe sway was pretty easy to get into for me.

When you buy something you do not have to think whether the developer deserves it or not, especially for software where producing more copies is free. You decide whether it is worth it for you.

When you donate, you think about whether someone deserves it and who deserves your money most.