Freebuild/survival server with that old school feel. There are cuboids at spawn, plus another survival map without protections for players who want the more classic, open survival style. If you want your own space on the survival side, you can also buy land through the Residence plugin and make your own cuboid there.
The server supports versions from 1.9.4 to 1.21.3, so a lot of different clients can join in. It mixes survival, economy, and a bit of PvP, while keeping things simple and familiar instead of overcomplicated.