It's definitely worthwhile to try to learn 1 new language. But learning 3 within the span of a year is very unlikely if you are an adult (and not someone extraordinarily good at learning languages like eg Kenneth Hale[0]). Try out learning one language in 2021, actually stick to it and practice every day, and if possible save up some money to visit a place where you can speak it immersively for a few weeks.

[0] https://en.wikipedia.org/wiki/Kenneth_L._Hale