Multi-color background on Mac startup, no icons or toolbar
I have tried every command to fix this situation (resetting the NVRAM, the SMC, booting in safe mode, etc.), but I get the same results--a multicolor background without any of the icons or the tool bar on top. The mouse and the keyboard don't appear to be connected. It just hangs up. I have also tried replacing the SSD, but I can't even get the background to show up. I cannot run in safe mode, nor can I get to the Disk Utility screen that allows me to repair the disk. Help!
[Re-Titled by Moderator]
MacBook Pro 13″, macOS 13.7