embedded software engineering is about understanding the hardware and leveraging its power through good architecture and smart thinking and understanding what the code you write will do. you can’t shortcut this by using a new programming language that does the work for you. you will still need to understand the low level details. so, learn C++ and familiarize yourself with the related embedded standards for reliability and safety.
adding rust into the mix will now require you to maintain code in not one but multiple languages as you cannot get around C or C++ and possibly assembly. it’s already complicated enough as it is, and you should focus on understanding the principles instead of learning another set of syntax and implicit logic.