Answer 1

There is no Rust course at the moment (I didn't find one in the community section either).

Yes, Rust and R are different programming languages.

There are some learning resources on Rust's website
https://www.rust-lang.org/learn
https://doc.rust-lang.org/book/ch00-00-introduction.html

Also:
https://www.geeksforgeeks.org/introduction-to-rust-programming-language/
https://www.javatpoint.com/rust-tutorial
https://www.w3schools.io/languages/rust-tutorials/

Answer 2

Also you can check these :

https://www.sololearn.com/discuss/3102552/?ref=app
https://www.sololearn.com/discuss/3092662/?ref=app
https://www.sololearn.com/discuss/3086837/?ref=app
https://www.sololearn.com/discuss/3091824/?ref=app

Answer 3

There is also a playground:
https://play.rust-lang.org/