I’m having a problem installing umbrelos

Good morning not sure if I’m doing something wrong.

I’m trying to install the OS.

I’ve used Balena Etcher to make a bootable usb.

The computer is connected to the internet via ethernet cable.

I switched the computer on and instructed to boot via USB.

But nothing happens I just get a white dot in the left left-hand corner ?

Is there something else I need to be doing?

Any advice would be grateful.

Is it a new or an old computer? Do you have Secure Boot turned on in the BIOS?