Is this really for “beginners”.

I just joined, and just started lesson 1 with the "trill warm-up".  Right off the hop, the instructor talks about using the 1-5-1 pattern. I have absolutely no idea what that is. I have no musical experience and was under the impression that this course was appropriate for people like me. Is it?

Hi, Minty! Melodic patterns (using "scale degrees") are included for clarity, but you don't need to know what the numbers mean in order to do the exercises. 

If you're feeling out of your depth, I highly recommend these courses first:

https://www.30daysinger.com/tutorial/how-to-sing-in-tune-for-beginners-part-1

https://www.30daysinger.com/tutorial/how-to-sing-in-tune-for-beginners-part-2

We have several other courses on intonation & ear training if you'd like to focus on that before the beginner (technique) courses. Hope you find the above helpful!