New Theatrical Edition - I want to build a Git server with GCP's free tier - GCE that gets charged, and a workaround: chroot on a home server?

Hello, I'm incompetent.
I tried to build it with the free tier and failed. Honestly, looking at the VM's status, it seemed to be within the free tier. Could it be that I hit a CPU burst? (But it doesn't feel right since I wasn't temporarily charged.)
So, feeling frustrated, I stopped the VM.
※Apparently, according to Nyaos-san, it seems CPU bursts are unavoidable after all.

Workaround: chroot?

I wonder if I can manage by using chroot, which is an old technology in the history of virtual environments. If I put Debian or something on my home server's USB and chroot there, everything can be executed under a 'prison' environment, allowing complete isolation.
Ultimately, the goal is:

- A Git environment where I can throw anything, safe even if the home server's SSD or HDD dies.

So, I'm wondering if I can set up an execution environment by putting GNU/Linux on the 64GB USB I bought cheaply the other day.
It seems there are also people who are quite extreme, going with 'Docker and chroot, Go!'
A simple container deployment tool combining Docker and chroot

My usage of Docker is not running it completely on my home server; I only use it on my everyday ThinkPad when I want to quickly test and run something.

Hmm, but honestly, the desire to rent a separate VPS somewhere else is stronger right now.
Should I go for Aeza, which has been a hot topic recently?