MacBook Pro won't boot.

If your Mac doesn't turn on or start up - Apple Support

Read and follow all the recommended solutions, all the way from the top to the bottom and everything in between.

Seen it happen before. In my case the boot volume was corrupted and that's the most likely reason for what you're seeing. There are variations on this including repeated restarting or immediate shutdown after getting to the same point. Some just freeze. About the only way to fix it is to use a new volume. I saved my old drive in hopes I might recover some of the data and cloned a backup (from an external drive) to a new drive.

There are a few things you can try. The easiest would be to install a new drive and then use Internet Recovery to format it and then install MacOS. Then if you want to look around the old drive you could use an external enclosure.