Are you a game master, worldbuilder, or a storyteller? We offer a tabletop campaign manager and worldbuilding tool that makes it easy to organise, plan, and enjoy your TTRPG campaigns. We are community driven, and best of all, our core features are free!
Do you use an online campaign manager? If so, which? I only know of Kanka so far, and am pretty happy with it. Edit to add: Obviously there are self-hosted wikis and other sites you could use, but this is the only purpose-built one I've used.
I use Kanka myself. I really enjoy it and love that it does what I need for free. I used to support it with a subscription when I had an active campaign going, but now that it's been dormant, I stopped. That said, I like that it's not necessary to do so to get a great tool for campaign building/management.
Other than that and WorldAnvil, the other big tool I've heard people use is a OneNote file. Not entirely sure how that works, but it's an interesting (and offline) way to do it.