I’d recommend anything that you are personally really interested in. Because there is plenty to do and getting good at one thing takes a lot of time. The engine can be extremely stressful at times as well when it doesn’t do exactly what you want it to do, some code is just not OK / buggy. Stay away from blueprints if you can for exactly that reason.
If you enjoy creating logic for animation blending, or like creating visual effects, like to visually create shaders then those are things I think this engine provides really good editors for.
Many code related tasks are a pain at first but once you get to know the engine programming is actually really smooth especially implementing new modules, working with arrays etc all the standard stuff more difficult in pure c++ is just easy in unreal. The exception is that some parts such as the widget system are pure garbage code and you might as well spend a month on something you’d do in a day with html + css. It is outrageous.
If you want to do math or shaders, check Freya Holmer on youtube. If you want to learn the blueprint / kismet basics, check Matthew Wadstein. If you want to get started with programming just start anywhere really but dump blueprints as soon as you can for c++.