Fitbit to Apple Watch

I would just Google whatever you want to do and then watch a YouTube video.
I like mine for notification of phone calls and messages, instant weather / temperature, recording exercise, the odd bit of meditation etc.
It takes time to decide on what you want on the actual watchface. I have date and time / weather / heartrate / exercise.
I turned off fall notification after it wanted to call the emergency services when I was sawing a branch. 😂

Go back to the shop where you bought it. Or if you got it online ask someone who knows how to do this stuff to help. Good luck. I know I couldn’t do it.
Out of interest I have a Fitbit watch and ( after my dd connected it) it does the things you mention so why did you decide to change?

It’s very intuitive. Just link it to your iPhone.