dont waste your time watching or reading anything if it isn't a timing guide before you've made several maps, none of the information will stick in your head if you have no experience of your own
plus when you're new misunderstandings and poor advice can be really damaging, binging pishi's videos made my maps really boring when I was new so I'd actually recommend steering away from guides like that. context is everything, generalised guides are way less useful than actual feedback about a specific map
For recommendation, i recommend mapping drum n' bass song because the rythm is mostly simple and it's easy to understand and map like this song https://youtu.be/biRISNWyg_k , Any other drum n' bass would be do fine. And probably my best tips is to make a map that you can play with so yourself can know what's the part You need to improve and the last tips is to learn more about patterns, combo color using, slider shapes, and timings.