First one has to focus on basic logic and machine.
Understand Mathematics and Logic fundamentals:
Probability, set theory and statistics helpful to build logic.
Fundamental skills of mathematics are required.
Basic of logic like truth table, Turing machine etc.
Understand Data and Data structure:
Understand data, data relationship.
Stack , queue and linked lists are essential for computer programmer.
Modern day programmers may not focus on this things, when you can have many articles on Python , Java, Photo or Angular to learn and get i to job.
But these basics would make you brain understand any programming language better.