Ask HN: How to do side projects while you are busy?

Hi. I am a CS student in a mediocre state school. Having changed my major to CS from economics in my junior year(just a year ago), I am unexperienced in software development.

I graduate in 1.5 years, and I need to be more prepared in order to get an internship next summer and a job soon after, in a good IT company.

I did very well on my intro CS classes and data structures class, and thought that I learned a lot, but the coding interview questions on cracking the coding interview book were a bit too challenging for me. I was able to finish only three chapters during this break.

I came up with an idea about an android app that I would like to develop, but this is not going to be easy for me, either.

Anyway, I want to either develop this app or study for some interview questions while I am busy taking four CS courses and participating in one research this semester.

How would you manage your time and stress to juggle all these things if you were me?

Also, which one should I spend my time doing, side project or interview questions?

Thank you.

p.s.: This is my first time submitting a question here, and I wonder if this question is improper for this forum. If so, please point it out to me, and I will try not to ask this kind of questions.