Hello nanna240,
Thank you for using Apple Support Communities!
We understand from your post that your new Apple Watch and iPhone are not showing the correct amount of steps counted and are not syncing to the Health app on your iPhone correctly. Make sure both your Apple Watch and your iPhone meet the system requirements listed below:
Set up your Apple Watch - Apple Support
"To set up and use your Apple Watch, you need an iPhone with the latest version of iOS. You also need to make sure that your iPhone has Bluetooth turned on, and that it's connected to Wi-Fi or a cellular network.
watchOS 7 is compatible with Apple Watch Series 3 and later and Apple Watch SE. Upgrading to watchOS 7 requires an iPhone 6s or later running iOS 14 or later."
If both devices meet the system requirements, restart both devices:
Restart your iPhone - Apple Support
How to restart your Apple Watch - Apple Support
Calibrating your Apple Watch as described below may also help:
Calibrating your Apple Watch for improved Workout and Activity accuracy - Apple Support
If the issue persists after completing the above steps, you may need to contact Apple Support for additional assistance.
Get Support
Best Regards.
