Ask HN: How do you manage your time with multiple projects?

This question is not about multitasking (doing multiple things at the same time). This is question is more of a framework for short-term and long-term learning.

I will explain this with my situation:

I am working on a personal project (say P1) that I would like to ship soon (may be in 2 months). I also have few more ideas of new projects that I would like to work on sooner. I would also like consistently add value to P1 in long term.

Additionally, I have curiosity about information retrieval (currently reading a book and plan to start an open-source project to learn how the fundamentals work).

To add more to this, I have a full-time work to do.

As you could see, there are so many things that I do (at least I feel) and so many other things that I plan to do. I try to manage all of this work with Asana tasks, but still I feel that I could be more effective. I look for inspiration and see people like Elon Musk and wonder how do they manage to run multibillionaire companies? We all have 24 hours in a day.

So my questions are

1. How you manage multiple projects efficiently?

2. This is an art and I would love to learn this skill

3. What resources (books, courses, talks, your experience) you would recommend to learn and gain this art?

Thanks for reading this far, appreciate your time spent