Hello and welcome to the forum :)
You can use SQL Express which is free or yes you can use Postgres on Windows as well. You would need to install Postgres, and install psycopg2 in your Python environment (pip install psycopg2). There are example local_settings.py files and an SQL file to show you how to create a user/database using psql in the deploy/postgres/ directory.
Please note that while it's likely to work completely fine, I do not test Postgres on Windows and can't provide much support if there are issues.
Randy