Running games on systems other than Windows can be frustrating and hard to do. Thanks to an app ported to FreeBSD it is actually very easy to play minecraft on FreeBSD. This application is called "Prism Launcher". To install Prism Launcher do the following:
 	pkg install prismlauncher
Once this is installed open it and you will get to add instances to set up various clients. You can have multiple versions and multiple modded clients set up so going to a version 18 server is just a click on your version 18 client. Below is a screenshot of prism launcher with my clients set up in it.

You see I have 4 clients set up. a 1.18 and a 1.21 and a modded to death 18 called plexiglass mountain. To create a new instance you right click on the window and choose your version. It runs flawlessly.