As mentioned in my comment, a batch script seems like the easiest way of doing this. If you're on Windows, this should do what you need:

start cmd /k "cd C:/yournodeproject && npm start"
start cmd /k "cd C:/yourangularproject && npm start"

• start runs a command in a new window.
• cmd /k allows us to pass a string into the new command line.
• Each window switches to the relevant directory and runs npm start.

Unfortunately I don't know enough about Bash to offer a Linux equivalent, but hopefully this will get you started.