Online graphic design class?

Does anyone know of any good online graphic design classes? I've read online that you can find good ones onlines, and some are even free. I don't trust that these classes are actually worthwhile. I don't want to waste my time combing through online classes that aren't worthwhile.

My favorite site is Lynda (link included). We constantly referred to Lynda coursework in my Visual Communication & Design course in college.
My university has a license with them, but I do know that they offer a free trial for a month to test out the site.
Skillshare has a ton of courses covering many topics. I've actually been watching several graphic design courses on the platform. I would recommend starting with Graphic Design for Beginners Part 1 - Learn and Apply Graphic Design Principles in Projects. It is the first in a really good course series that I found to be very helpful and informative. Skillshare costs $15/month, but I say it is well worth it. Since I am a member, you can use my referral code and get two free months to try it out. Full disclosure, I do get a free month if you sign up after the free period but honestly, I would recommend it even if that were not the case.

Here is my referral code that anyone can use: