Nannou is a library written for the Rust programming language. Thus, the first step is to install Rust!
To install Rust on Windows, download and run the installer from here. If you're on macOS or Linux, open up your terminal, copy the text below, paste it into your terminal and hit enter.
curl https://sh.rustup.rs -sSf | sh
Now Rust is installed!
Next we will install some tools that help IDEs do fancy things like auto-completion and go-to-definition.
rustup component add rust-src rustfmt-preview rust-analysis
Please see this link if you would like more information on the Rust installation process.