How to build custom handrail?

Looking to build and install a handrail on the right side (as you head up) of a plaster wall. I have virtually no experience with finish carpentry, but I am somewhat handy and eager to learn (new homeowner watching lots of YouTube videos).

I’m very green to carpentry and any detailed steps or tips would be very appreciated to tackle this project. I would need to buy a mitre saw. I have a dewalt pancake compressor and nailer. Is that sufficient to nail the returns to the wall? How would I make the first angle cut when the slope changes? I’m thinking one piece with the angle change and returns at both ends. The turn at the top would be one separate straight piece with returns at both ends. Avoiding making the turn for simplicity and understand it may not be up to code.

Thanks!