Answer 1

Here is a guide to using the pip package manager
https://realpython.com/what-is-pip/

And another one about venv and virtual environments, which is the recommended way to develop python, including with vs code.
https://realpython.com/python-virtual-environments-a-primer/

The two topics are interconnected, so get on with reading ;)
https://code.visualstudio.com/docs/python/environments