Typically, most software projects will have dependencies that need to be installed before you can begin to work on the project. This will most likely be mentioned in the README of the project, but if not, you will have to explore and find out yourself.
Most node/js projects will use npm as the package manager, so you can just run npm install
(or yarn) in the package directory and it will install everything for you (provided you have node & npm or yarn installed on your
computer already).
Most python projects will have a requirements.txt file with all of the packages needed. You can
install these with pip install -r requirements.txt.
Some projects don't have any dependencies at all. This differs based on what languages the projects use, and who writes them, so reading the README is the best way to find out.
Once you have all the dependencies installed for your project (none are needed for this one, hooray!), it's time to add your contribution.