Course says 2020. Is this still applicable and good for preparing for Google Certified Associate Cloud Engineer ?
I would say "yes and no".
The majority of GCP user interface and features have changed since the course was filmed, so if you want to follow along it will be harder as you have to figure out "where to click" on the real interface. Also lots of new features were introduced and existing properties have changed ever since. You will need to combine this course with lots of actual practices and also referring to Google Cloud documentations to keep up.
However, course’s syllabus is still usable at certain points. If you don’t know where and how to start, use the course as first guideline to prepare. But as said, you need to work a lot to compare and comprehend the difference between what shown in the course vs what the reality has. One usual method is to compare the official exam guideline with what the course presents, to know which part is mentioned and which is not, then having extra learning if needed.
Just to share, I got my ACE certificate in mid-2020, and by the time I took the exam, the course has already been a little bit outdated.