While hosting a server, press F11 then F4. On the menus to the right of the screen, try messing around with some of the selections. If you click "Shapes" then you can spawn any model shape that comes with Blockland or an Add-On you have downloaded. If you do it in an Internet server it'll work but people without those models may crash so it's best to stick to defaults. If you press F3, you can click on players/bricks and edit some of their settings, such as scale - write a new one and click "apply". To edit your own player you'll have to go into flying camera mode (F8 before opening the editor) first. In either of these modes you can also pick up players and vehicles and move them around. (Bricks are locked in place)