Hello, KathyW, and welcome!
Yes, I do think it can be possible to take up knitting after a break of 20+ years.
It sounds as if you did quite a bit of knitting and crochet too, since you took that up. This means you had plenty of practice and muscle memory when it came to manipulating your needles and yarn.
If you don't want to launch straight into the shoes you can always do a test piece first to see if things come back to you.
If you find you need a refresher on anything then the videos under the 'Free Videos' tab at the top of the page and YouTube are good places to start. And, of course, if you have any questions you can always ask on the forum.