Problems with my phone

Try a forced restart and see if that fixes things.

iPhone 8 or later: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Press and hold the Side button until you see the Apple logo.

To turn it off: Settings>General>Shut Down---> last option at the very bottom.

To make a forced restart:

Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Press and hold the Side button until you see the Apple logo (it might take several seconds). When it appears, release the Side Button, wait for your device to restart, then test it.

Outgoing phone call: what error message are you getting? Have you already talked to your carrier? what did they say?

Regards

Giulio