|Prince Arjuna and his Charioteer Krishna|
There are many more resources collected here in Kali's Kitchen. Make yourself at home.
As one of the most important symbols of yoga, Om is a whole subject in and of itself. As a starting point, you may like to read this Kali's Kitchen post on The Meaning of Om.
The Cambridge Introduction to Sanskrit is the best text I've seen on the subject and is the text used in the University of Alberta's Sanskrit courses. You can find alphabet charts, sample chapters, practice sheets, and more here.
Here you can contemplate more of the Vedantic Nyayas or metaphors about illusion (maya) and reality, like the examples I gave of "The Rope and the Snake" (Rajjusarpa-Nyaya) and "Water off a Lotus Leaf" (Padmapatra-Nyaya).
And most importantly for your studies, here is a previous post with a full and detailed recap of my lecture.
Thank you for this opportunity! Best wishes on your path!