The switch to Forgejo is super easy, if you don’t mind everything being called “Gitea” you can just switch out the Docker image and carry on.
I just switched recently, maybe around version 1.19.
Forgejo is also working on federation which will give the system an advantage moving forwards. They’re also sticking with Gitea as an upstream source so reasonable changes Gitea makes should make their way to Forgejo pretty quickly.
Without more info it’ll be hard to help.
I got it working in principle, but the Raspberry Pi I wanted to host it on isn’t powerful enough to handle the necessary computing.
Still no worse than the worst of the male grifters.