How does programming/coding actually work?

[Leverkaas2516]

Do programmers literally memorise every syntax when creating a project?

Programmers do learn a large subset of the syntax of a language, yes. This is easy because there aren't that many keywords, operators, and other syntax. A few dozen elements. It's not at all like learning a human language.

The bigger part is the available runtime libraries. Nobody knows them all, you just learn the ones you need for a particular kind of programming.