I don't have harddisk space to install new OS from USB what now?

Hi,

I followed steps to set up Sequoia on a USB with OpenCore.

Next I rebooted my Mac, selected boot EFI and then Install Sequoia.

I agree to terms and services, and then get an error that I have 100mb too little space on my HDD to install the new OS.

I backed out of the install and now I have no OS on my machine. Can I somehow delete stuff from my HDD so that I can install an OS?