Any suggestions to make in my open world / fantasy game?

Oh, and add characters like sentries into your game! Use these guides:

https://forum.creative.gimkit.com/t/how-to-make-a-talking-and-trading-sentry/2250?u=haiasi
You can add some green bushes on top of them to make them look like goblins (make sure the bushes are on a higher layer than the sentry)