Question

Shalom!!
Does the Rabbi have a column that talks about the definition of the Oral Torah?
I heard in one of the Rabbi’s lectures that Moses our Teacher didn’t actually know what the thirty-nine primary categories of labor were, and I’d be glad to understand what the Rabbi meant. Does that mean Moses selected and wrote on the Sabbath but didn’t gather wood?
How much of what is in the Talmud is from the Amoraim, and how much was really given at Sinai? Is it possible that even “totafot” were not the tefillin familiar to us in the time of Moses our Teacher, or for example in the First Temple period? Why was the Written Torah given without interpretation, and how did people manage for thousands of years without an agreed-upon interpretation, with each person having his own interpretation, and then suddenly the Talmud wrote down all the explanations?
 
After all, our usual claim against the Karaites is: how can it be possible to observe the Torah without an accompanying interpretation of the book? And now I’m discovering that even for us, these things were not really received together with the Torah, but developed over the generations?
What did they observe when Moses our Teacher came down from Sinai??