This is a great idea! Doing this effort early will give you a lot of options. Even if you only get to a foundational level in all 4, your future self will thank you, because you can pick any of them up and take to conversational fluency at a later date. I'm very curious of course what your process will be. There's no 100% correct way to learn a language, so I'm sure you'll develop a strategy that works for you.