The only command that you should need to start the application is docker compose up.
Note that you have to install docker first.
Open http://localhost:3000 with your browser to see the result.
If you are using a windows machine open the start.sh file with vscode. Click on the button on the bottom right of your screen marked with CRLF. Now change the encoding of the file to LF. After that you can run docker compose up.
This is a simple example how to use prisma and postgres with your nextjs application and dockerize it.