@alex Three cheers!
The health and novelty of the Fediverse is many instances partially overlapping (instead of a few big ones, or one giant one). To that end, starting an instance is good for the one-to-few users and good for the Fediverse as a whole.
There is a getting-there app called "Social" that is built into NextCloud, and there are many free / cheap NextCloud providers. This is about the lowest bar I know to staring an instance.