how are we supposed to learn this?

Question

please some one explain this to meeeee

Answer 1

data_types are nothing but what type of values are stored in the variable.
int a;
a is a variable which can store an integer

Answer 2

As you go through the tutorial also check the comment section beneath, I find that helps.. But if you still feel stuck, try video tutorials on YouTube as there is plenty there to explain it further..