Hi. I started singing a couple of days ago. Sorry if I am bringing up a topic that is covered in later lectures, but I am feeling anxious about my practice routine. I am willing to practice about 40-60 minutes a day if it doesn't hurt. What should be the ratio of vocal exercises to song-learning in my beginner practice routine? I don't mind only doing exercises if it is the most beneficial. But maybe exercises (like lip trills and stuff) are only meant for warm-up? Should I spend 70% of my practice time singing some song or should I focus on doing abstract stuff until my sound improves?

What would you recommend? Thanks in advance.

With that amount of time, I'd recommend 10-20 minutes of warmup/exercise, with the remainder of your time spent on song work, listening, and/or ear training. Hope this helps:

https://www.30daysinger.com/blog/one-lesson-per-day-how-to-practice-for-the-best-results

https://www.youtube.com/watch?v=gwzvDGmHJvQ