Creating a new map
First things first. To create a new map, go to File > New and call your new map 'tutorial'. The other options are just fine so leave them be.

And the first thing we'll want to do is generate some terrain so that we may walk on it. So open the Terrain Editor window by going Terrain > Edit Terrain. once you're there, go Tools > Generate Terrain to generate some random terrain. When you've done that, click OK.

Now we need to generate the surface texture, so go File > Generate surface texture. When the dialogue pops up, you can just click OK.

Now you should have some islands surrounded by water. The islands are quite boring at the moment, so let's liven them up and give them a texture. Open Terrain > Texture and click on the
New Layer button (it's next to the red X). Call this layer 'ground'.

Press Enter to finalize the layer name and then select your layer by clicking on it. Now click on the
Edit surface Types button. Create a new surface type (click the add button) and then double click to rename it. Rename it to 'ground' - reflective of our layer name.

Now click on the
Material Editor button to open it. Navigate to the Materials > Terrain directory, and select
beach_white_sand.

When you have selected it, close the Material Editor and in the Surface Types editor, click on
Pick Selected. Then click OK. Now back in the terrain layers editor, select the ground layer and select 'ground' from the surface types dropdown box.

Once you've done that click on the 'load texture' button. You should end up in the /game/textures/terrain directory - if not, click on the terrain button to the side. Open
beach_white_sand.dds.

Now click OK in the terrain texture editor. Click 'Layer Painter' on the RollupBar (the sidebar) and move the radius slider all the way to the right, and make sure 'ground' is selected as the layer. Move your mouse into the perspective view (the 3D view) and left-click to paint your layer.

Now our terrain is textured - so let's see if we can jump into the map and walk around in it. Go File > Export to Engine, save your map (File > Save) and then restart Sandbox2. Reopen your map. Now place your camera over some terrain and press
CTRL+G (or Game > Switch to game). You should now spawn in your map where the camera was, and you can move around. Play around for a while if you want.