Here is a similar question and its answer:
It should give you some idea. If you still need help, let me know.
Anyway here is the idea:
- As you have said, first you need to define the input mappings in the project settings
- Within you Actor blueprint, you need to override the events for these mappings (right click on blueprint editor and type the name of your mapping and it should popup in that list. Click on it)
- Once the event node is on the blueprint editor, you can tell it what to do. In your case you need to update the rotation of your Actor. simplest thing you could do here is to add some rotation (based on input value and how fast you need it to rotate) to your Actor.