Hi Donna,
It seems you're having trouble syncing some devices with your iPhone 6s. It's important for you accessories to work as expected, and we can find a fix together.
Do you have any other Bluetooth accessories that have this issue?
You'll want to make sure Bluetooth is enabled in Settings > Bluetooth, then follow the steps listed here to download the app and begin set up:
Setting up your Samsung smart watch with or without a phone
If you have further questions about setting up your Galaxy Fit, you might ask for help with Samsung on the support site linked about.
Thanks for using the Apple Support Communities.