Please, a simple and direct answer... I know nothing about computers, so don't say modify your .ini and then open the download of /:C and then hex edit the bla bla bla...

How to make a simple server where me and 2 other friends can play?

We want to train...

If you don't need anything big, then you can simply use a listen server. All you need to do is open soldat, go to the options tab and set up your server settings (Either make sure 'Register to Lobby' is checked and give your friends the game name and password, or uncheck it and give them your IP address (if you don't know it, goto http://ipchicken.com)), go back to the start game tab and set up your game mode and point limits, and then hit start game.
Yeah it proably still looks complicated if you know little about computers, but this is as simple as I can explain it. :o

Thank you.