Utter noob guide to this docker stuff

[Egosumumbravir]

Right, so the first time I've used docker is about 10 minutes ago. I'm still trying to wrap my head around it.

I'm totally lost in getting this working so hoping someone wouldn't mind walking me through this in more detail.

Current Windows 10, up to date with whatever the patch Tuesday 2 days ago was.

"Docker Desktop Installer.exe" downloaded and installed. Is it supposed to be WSL2 or hyperV?
I've just installed as defaults.

"python-3.10.8-amd64.exe" downloaded and installed. Add python to path ticked. "pip install pyside2" run.

"videobench-master.zip" downloaded to D:\ and extracted to D:\videobench-master
admin command window launched on that D:\videobench-master\ folder and "docker build -t docker-videobench -f ./Dockerfile ./" executed. This takes some time to run through 14 steps.

... and now what?
Where exactly do I execute "python videobench_ui.py"
Running it in the local windows command window gives the anticipated GUI which then fails with can't open file errors and "python not installed, get it from the msstore"