Is there any good introductory material? I have tried severally to understand the theory and the spirit of DL and ML, but I have not been able to connect the dots. Please direct my path.
Calculus, Linear algebra, Statistics, Probability theory. You won't get far studying "basic" ML without an elementary understanding of those subjects. Unless you blackbox the implementations and hack them, but you'll have trouble understanding why things work/when to use certain techniques vs others or how to tune for optimizations.