How to move/rotate the player specific ammounts on keypress?

I’d like to try and make a control scheme a bit like old dungeon crawler type games, stuff like Wizardry, or more recently Grimrock.

I’m starting from the default FPS Blueprint project, but I’m not really understanding the MyCharacter BP so well. How does the project even know what the proper inputs are (WASD) is this hard-coded and outside of the BP mechanics?

For example I’d like my character to move forward a fixed distance when hitting W, or rotate 90degrees when hitting A, I’ve tried quite a few things in the MyCharacter BP but with no success. Any help would be quite welcome, and sorry for the probably fairly noob-ish question.

You may want to have a look at my post here. It briefly explains how key mapping can be done in UE4.