It’s a good idea if you understand the basics of it, in particular when it can be useful (IE matching something following a pattern rather than a specific string). Outside of that, you are likely to most of the time be able to google the exact syntax when you run into needing it.
Depends on if you just want to “get by” or want it to be actually useful. Once you get even mildly comfortable with regexes, you find uses for them all the time. They’re very powerful and quite convenient.