Linked lists are one of the most fundamental data structures taught in computer science, even when they are practically one of the worst performing data structures. Conceptually they are simple; however, implementing one in a program language is a great experience to learn from.
Rust is notorious for being difficult to implement linked lists in. However, there is a fantastic guide called Learning Rust With Entirely Too Many Linked Lists. If you already know the basics of Rust, I recommend starting in Chapter 5 onwards which moves from safe code to unsafe code. Many topics such as panic safety, variance, stacked borrows, etc. are also discussed.
Anyway, if you have never read the guide, I heartily recommend it.