My MacBook Air 2017 won't boot up (shows no entry sign)

My MacBook Air refuses to finish the booting up process.

While I was working, it froze so I forced a shut down by pressing the power button. When I tried to restart it, it now shows the "no-entry" sign (circle with a diagonal line across it).

I also know it was very low on space and this likely contributes to the issue. This issue has happened once before and my university’s IT department were able to get the machine up and working again.

Please advise.