In these ot's you've downloaded, have you found any complete (or mostly complete) data packs. Map, map editor, item editor, and basically pre made? So almost a plug and play setup.
I downloaded one like 10-15 years ago just to mess around with on my free time and it was so simple. I remember just running the exe file, ip changer, and logging in. Then to edit item or creature data, each one was just a simple word file.
I've looked around and The Forgotten Server is where everyone points me, but it seems a lot more tricky than the ones I remember from long ago.
I'm pretty disappointed I never saved my old hard drive for this reason haha.