- There are servo examples (sweep and know) in the IDE. You can start with that.
- You can find examples for the L298 on the web. Try them till you have one working.
- For the nRF24 you can look at this tutorial; I'm sure that you can find more on the web.
All the above just with one individual component, don't try to combine them while getting the experience.
Once you have it all working and understand it, merge them into one sketch.