Thank you for your interest in contributing to Rust! There are many ways to contribute and we appreciate all of them.
Documentation for contributing to Rust is located in the Guide to Rustc Development, commonly known as the rustc-dev-guide. Despite the name, this guide documents not just how to develop rustc (the Rust compiler), but also how to contribute to any part of the Rust project.
To get started with contributing, please read the Contributing to Rust chapter of the guide. That chapter explains how to get your development environment set up and how to get help.
The rustc-dev-guide is meant to help document how rustc –the Rust compiler– works, as well as to help new contributors get involved in rustc development. It is recommend to read and understand the rustc-dev-guide before making a contribution. This guide talks about the different bots in the Rust ecosystem, the Rust development tools, bootstrapping, the compiler architecture, source code representation, and more.
There are many ways you can get help when you're stuck. Rust has many platforms for this: internals, rust-zulip, and rust-discord. It is recommended to ask for help on the rust-zulip, but any of these platforms are a great way to seek help and even find a mentor! You can learn more about asking questions and getting help in the Asking Questions chapter of the rustc-dev-guide.
Did a compiler error message tell you to come here? If you want to create an ICE report, refer to this section and open an issue.