Has my Macbook Air been hacked?

If you're hacked it would not be visible in the terminal like this. Also, Macs are difficult to hack, I understand your concerns with this phone name showed in terminal. Do you have a phone like this or not?

If you don't have such a phone please boot your Mac in the safe mode to see if the issues persist. If the issues does not persist in the safe mode, It has likely been caused by an external piece of software, you might want to evaluate the software installed to your Mac

The steps for booting your Mac in safe mode differ wether you're using a Mac with apple silicon or an intel mac

Start up your Mac with Apple silicon in safe mode

1. On your Mac, choose Apple menu  > Shut Down.
2. Wait for your Mac to shut down completely. A Mac is completely shut down when the screen is black and any lights (including in the Touch Bar) are off.
3. Press and hold the power button on your Mac until “Loading startup options” appears.
4. Select a volume.
5. Press and hold the Shift key, then click Continue in Safe Mode.
6. The computer restarts automatically. When the login window appears, you should see “Safe Boot” in the menu bar.

Start up your Intel-based Mac in safe mode

1. Turn on or restart your Mac, then immediately press and hold the Shift key until you see the login window.
2. Log in to your Mac.
3. You might be asked to log in again.
4. On either the first or second login window, you should see “Safe Boot” in the menu bar.