What are some good resources for learning new skills online?

I can only tell you what I use. For physical skills (cooking, crafts, repair and maintenance, homemaking, etc.) I go to YouTube. For everything else, I start with LinkedIn Learning (used to be lynda.com). I can usually stop there. If I need more than what I can get with LinkedIn, I use Gale Courses which are offered for free from my local public library. If I need more than that, I’d look at online courses offered by a community college, because they offer great courses that are usually cheaper than universities. If I couldn’t find what I need there, I’d look at university courses, starting with where I earned my doctorate (Athabasca University) and my masters (University of Calgary).