Kind of a Fail...

So I was wondering how to test out my Gamemode without having a server or something.

Because I remember some versions you just open then Create Multiplayer and there would be an option to select a Gamemode.

How do I still do that?

Press ‘Play Game’ from the main menu. Select a map and choose your gamemode.

Well I tried play game I chose a map but I only get Start Multiplayer and Start SinglePlayer.

On the right hand side there are three icons. Click on the bottom icon.