First off. Try joining #modhelp ingame and ask specific questions there, as you'll get simple questions answered fairly quickly.
The best way to learn how to map is just to practice mapping. Having some knowledge on how music generally works is a huge plus as well.
All of the guides in the
compendium are great to read in addition what you've already looked at, so give those a shot if you're looking for guides, tips, and hints.
Also keep an eye out for the seasonal mentorship program, as you may be able to find someone through it to help you improve your beatmapping.
t/617542