There is no need to create a sample map/level in the UDK to test with, as the UDK already has 7 sample maps that can be used.
To create a standalone game, that friends can log into and play, follow these steps:
Step 1: Launch UnrealFrontend.exe, normally located here:
Step 2: You will see a Menu at the top, under that some tool buttons, and under the tool buttons two tabs, called Game and Cooking, select Game. Click on Browse, next to the Map to Play box, and select one of the sample maps. I chose DM-Deck.udk
Step 3: Select the DM-Deck text in the Map to Play box, and copy it, then click the Cooking tab, and paste the text into the Maps to Cook box, then return to the Game tab.
Step 4: Leave (Use cooked map) unchecked, and in the Common section, leave all unchecked, except Multi-threaded.
Step 5: In the bottom section, PC, for server type choose Dedicated (Listen is to serve a game and also be able to play it from the same PC, but you will need a highly specified PC to do this well, so it is better to leave it as Dedicated), and for number of clients choose 0 (this is not the number of clients that can connect to the server, it is the number of clients that will be spawned on the same PC). Set the Resolution to 800x600 (can be increased later, once a low resolution is known to work). Leave the Show Log and Remote Control boxes unchecked.
Step 6: Now press the Cook tool-button (fourth button under the menu bar).
Step 7: Wait a few minutes until it has finished, and you see the following message:
Step 8: Now click the Package Game tool button. The Game Settings dialog will open. Enter a GameLongName (First Galactic War) and a shorter GameName (eg FGW), then press the Package Game button.
Step 9: If you now go to your C:\UDK\UDK-2009-11 folder you will see the packaged file, UDKInstall-FGW.exe (this can now be distributed to friends).
Step 10: Upload your packed game to one of file hosting sites for your friends to download from.
To Install the Packaged File created from the procedure above, just double-click it.
Step 11: It will give you first the license agreement, then the Install Location dialog, using as a default: C:\UDK\GameLongName (so in my case this was: C:\UDK\First Galactic War). Now click on the Install button
Step 12: Next it will Install the Prerequisites for Unreal (if they are not on your system):
- Visual Studio 2008 Redistributables
- Microsoft DirectX 9.0c
- Charting Tools
- Nvidia PhysX System Software
The installation processes should then complete, and the game is ready to play.