The best language depends on what you're motivated in..
if you are a frontend guy: go for JavaScript/TypeScript - there is nothing else on the table right now to beat this.
Backend: Python OR Node (JavaScript). Later you could switch to more sophisticated languages like Rust, Go, C# or Java.
DevOps: Node/Go/Python/Rust
Start with one language first, create projects and understand the language.
Then migrating to another one isn't as hard as it looks from the surface.
GL my friend