The line between IDE and text editor is kinda blurry nowadays anyway. I don't know that much about Geany, but many of the text editors I've used were basically full IDEs, except that the IDE features were opt-in.

Currently I use VScodium as my editor, and I've been happy with it. I hear a lot of good things about Kate too, and as a KDE user, I feel like I should try it some time. Kate to me looks like the same spirit of text editor as Geany. Maybe if you're comfortable with that style of editor, give it shot.

The 2 editors that have really been catching my eye lately have been Helix and Lapce. I think it's really cool that Helix went with a Kakoune style "selection → action" system instead of the normal vim style "action → selection". I think Lapce is trying to be a similar style of editor to Vscode, with simple IDE features by default, but then an extension sytem to expand that. Maybe an editor like that would be approachable to you. Although unlike Helix, Lapce seems to be less production ready for now, so maybe wait on that.

For now you could of course just try VScode (or VScodium if you're like me and want open-source software) since that's a popular one right now.