"Sandbox failed to run: No Application is associated with the specified file for this operationAt line:1 char:1 + ./sandbox up

Following this guide here Algorand PyTeal Course | Setting Up Development Environment - YouTube

I’m getting stuck when I need to “./ sandbox up”
how do I resolve this issue? this is the last leg of setting up my local dev environment

It looks like you are on a PowerShell terminal.

sandbox only works on a bash terminal.
If you’re on Windows, there are two options: see GitHub - algorand/sandbox: Algorand node sandbox

I’m trying to run sandbox from VS studio. I can run docker normally from gitbash but im trying to understand if running the command from VS studio is suppose to start docker?

You need to switch the terminal in VS Code to be Git bash.
See Integrated Terminal in Visual Studio Code