Are there any Apple produced turorials on iMovie?

I think the link Rich has given you is probably the most comprehensive available. I must say that I dislike its format, making it necessary to click multiple links. It would be much better if it was compiled as a single .pdf book.

Regarding videos, iMovie is so complex that it would take tens of hours of video to give anything near a complete description of everything.

There are countless tutorials on YouTube. Some explain the basics to get you going and others go into detail on all the specific techniques.

Getting them all in one place is never going to happen. So you will have to resign yourself to searching for individual topics that interest you.

I share your pain as in the past I have searched for an all-in-one tutorial.

I'm not aware of any Apple produced video tutorials for iMovie that would be a comprehensive overview.

The best written tutorial that I know of is the online help menu that has step by step instructions for nearly all of iMovie's features. It also has a good search feature where you can search by search word or menu. Here's the link in case you are interested:

https://help.apple.com/imovie/mac/10.1/

-- Rich

Do not try to learn by watching a YouTube tutorial all the way through as it will just overwhelm you.

Play just one short section at a time and practise that bit before moving on.

It's also a good idea to jot down notes of exactly what to do as it's so easy to forget even the simplest procedure after you have moved on to the next.

There are several general tutorials here ranging from 15 minutes to a couple of hours.

https://www.youtube.com/results?search_query=iMovie

There have been numerous versions of iMovie over the years and it's important to get a tutorial that is based on your version so if you have the latest iteration of iMovie you need to check that the tutorial has been made in the last year or so.