Hey there lovely
First things first....
1. Does your network support tethering?
2. Have you turned tethering on on your phone?
3. If yes, there is a password on the tethering screen that you need to make a note of (or change it)
Then using the device you want to tether to your phone, search for it is connections then enter the password and it should work.
I am not employed by Samsung nor do I receive any remuneration as a Samsung Members Star.
My device is an S25 Ultra.