I had a quick look at a course about Go on Udemy. The videos on that were less professional in my opinion, but it may not be typical. I am not sure it had assessed coursework. I think that is valuable to ensure you are taking it in and that if you get a certificate then it is earned. Most other courses I have done recently have been on Coursera. There are plenty of good free courses on Youtube where you may get feedback from the creator. It went with Coursera this time based on previous good experience.