Waterproof no, but water resistant yes
https://support.apple.com/en-us/HT205000
This will give you a good overview of some of the things you can do on the Apple Watch
https://support.apple.com/en-us/HT205547
Whether it is worth it, is up to you. I got mine 2 years ago thinking I wanted the "Fall Detection" and "ECG". I could care less about those features, and now I like a dozen other features I never knew I was missing.
Weather on my wrist is huge, unlocking my Mac, when on vacation the tides so I know when it is good to walk on the beach, exchanging messages with my Wife, phone calls on my wrist (like answering the phone while riding my bike), tracking my exercise (not hardcore, but it encourages me to exercise, and stand, etc...), timing my hand washing (important with Corvid-19), getting ALL my iPhone alerts on my wrist (HUGE!), whether the iPhone app has an Apple Watch version or not.
There are many more features, but those are my top list.