That will get you a terrain baseplate (unless they changed it again!). If you want a brick baseplate go to your terrain tools and reset terrain. Then insert a Part and resize it to the size you want.
Open roblox studio and click New. This will open a blank skybox.
Insert a part call it base. Size it, Anchor it and lock it. Publish the place to roblox ,It will replace the place you have now.
.