The best basics course that I’ve found is Moogly’s (mooglyblog’s?). They have video and picture tutorials for everything crochet, but to start with here’s a link to their “Learn to Crochet” post https://www.mooglyblog.com/learn-how-to-crochet/
Search that blog for pretty much any stitch you need an explanation for, and they probably have a tutorial for it. It’s how I learned to crochet and I still use it sometimes; it’s a great resource!
They also have a whole bunch of free patterns. https://www.mooglyblog.com/category/free-moogly-patterns/
All About Ami also has some great how-to posts, focused more on amigurumi but with some more general ones: https://www.allaboutami.com/tips/
And the Make and Do Crew has a lot of tutorials: https://makeanddocrew.com/category/knitting-and-crocheting/how-to-tutorials/page/2/
That site (and All About Ami) also have lots of patterns with very detailed explanations, including pictures of video tutorials.
For basic patterns, I’d start with https://makeanddocrew.com/1-hour-free-crochet-hat-pattern-beginners/ or maybe https://www.allaboutami.com/knottedheadband/
One’s a hat, the other a headband, but both are made flat and sewed together once you’re done, and both have detailed tutorials (the hat especially).
tl;dr: Start with Moogly for beginning to crochet, stitch explanations, and some free patterns, especially if you learn best from videos. All About Ami and the Make and Do Crew both have lots of tutorials, but both tend to be more advanced than the Moogly tutorials (not all! There are some basics posts on both sites), and if you want to make amigurumi I’d say check out All About Ami’s site. For any other patterns, I cannot recommend ravelry.com highly enough. So many patterns! There are forums that I don’t really use but I’ve heard they are good! So many different ways to filter searches! Ravelry is the best, for both crochet and knitting.
If you ever have specific questions about a crochet pattern or have something you want to make but can’t find a pattern, I’m happy to help! I’m not as good at knitting as I am crochet, but I’d be happy to try to help with that too, or at least point you in the right direction.