I need help

I agree with julieda, it sounds like you have an original. Go to the Watch app on your iPhone, then General>About>Model. Then report that information. You can also tap on that number and provide the A#### that shows.

You're welcome. This should help you identify what series of Watch you have. Identify your Apple Watch - Apple Support

What series of Watch do you have? Original, Series 1, 2, 3, 4?

You probably have the Original Series.

Not if you have the original watch. I had the Original watch and upgraded last year to the Series 4.

If you have the original Watch, no. If you attempt to update the Watch and it will not update, then you probably have the original which cannot update past watchOS 4.3.2.