What do you want to do with activity (for me it is called ‚Fitness‘ in my country).
Do you want to use the rings and do the achievement stuff?
Or do you want to use the watch with the Video workouts?
If you want to use the rings etc. you dont need to do anything more than connect to apple health. The data is pushed towards fitness. But you must not have any apple watch connected to your phone!
I still had a connection to my apple watch and left it unused, but still saw all three rings and the phone just thought I would not do anything with my apple watch.
When I removed the connection from my apple watch to my phone in the watch app, I got only the red ring and got medals etc again.
"Fitness" in my country doesn't involve rings (unless it's gymnastics), it involves a funny little number called VO2 Max.
Get out there, log some activities and work towards building your VO2 Max by keeping your training load in the green. Use suggested workouts if need be. You've got a highly sophisticated fitness device that does a heck of a lot more than steps and standing minutes.
If that's all too technical, Garmin tracks your step count and your activity minutes. You can easily set goals for each on the watch. They're not "rings", but it's the same thing.
