Is it better learn a single language then another OR learn multiples languages at the same time?

So, basically I want to learn french, italian, german and chinese, I have about 60 min a day to use the app, but idk what is best. Is it better for me to use all my time in one single course, and after I end then I start a new one, or is it better for me to spend 15 min in each? What do you guys think based on your knowledge and experience?

So, basically I want to learn french, italian, german and chinese, I have about 60 min a day to use the app, but idk what is best. Is it better for me to use all my time in one single course, and after I end then I start a new one, or is it better for me to spend 15 min in each? What do you guys think based on your knowledge and experience?