This seems to be very popular and highly recommended in Reddit. She briefly talks about how she was scared off of maths at one point in her life and later went on to get a phd. She also has a book on the same topic. Note that the course is not math specific.
If I could do it all again, I’d start with an old school Calculus course. E.g “Calculus” by Binmore . It’s a decent and well explained introduction to Calculus and Linear Algebra and it’s useful maths. You have to get a hang of thinking in maths and doing maths you find boring.
From here it depends on what you want to do. There’s more maths out there than there is time so you need goals.
Which branch of math are you interested in?
Do you need it for something specific to your career or is it just a hobby?
What's you current level - are you comfortable with high-school level algebra, trigonometry, calculus?
In any case, I second the recommendation for Khan Academy as a good starting point - not only for the range of content and Sal's silky voice, but also for their approach to learning: you get to practice topics until you "master" them instead of just watching/reading, maybe taking a test and then moving on to the next topic.
If you get a teacher, or at the very least someone who is helping you, or even just learning alongside you, you’ll learn far more efficiently, as what the other person thinks may be put in a phrasing, or use a tactic, or have some reasoning, the list goes on, that you could never have come up with on your own. Even if you’re smarter than Newton - well - Newton didn’t get to where he got without a little help throughout his life.
That’s not to say it’s impossible. If you really have a love for mathematics, there a loads of ways to learn more math. If you’re looking just to get some random math knowledge, then roaming YouTube is actually a pretty effective method of gaining some fun knowledge. Those guys are average joes just like you and I. They always have something fun to get your hands on.
If, however, you’re looking for a specific subject, or something that would otherwise replace a class, then get the best textbook you can find and get a tutor. Maybe you’ll be fine on your own, but two heads are still better than one, especially with education. Math builds on itself. If you just barely scrape by in Algebra, Calculus isn’t going to be fun. You need to have a pretty good understanding of everything. That’s why its so hard.
One last tip: pace yourself. If you think you’ve got a topic after reading it and working on a couple of problems, still take a day on it. You’ll find something you missed, find a shortcut, or something, and it’ll make the next topic just that much easier. And again, that’ll carry on.