they say those are good business, but i am struggling to absorb them... It's hard. What do i do? what practice do i learn? especially cloud computing... there's this test in alibaba academy, and i barely get passing grade on its introduction course.

Then 3d printing has all these bunches of arduino bullshits and writing dot H files from scratch which is completely confusing idk. Please assist me... especially if you have experience with them, how did you FIRST get into learning it back then?