how to use libraries?

how do i use a library that comes with the software and also how i do i use custom libraries that other people made or libraries a.k.a classes that i’ve made?

in c++ for normal library with would be #include <lib_name> and for custom libraries aka self made .h file it would be #include “lib_name”.

what’s the syntax for arduino?

in c++ for normal library with would be #include <lib_name> and for custom libraries aka self made .h file it would be #include “lib_name”.

No, it wouldn’t.
It would be #include <lib_name.h> or #include “lib_name.h”.

The same syntax applies for the Arduino. The difference is in where the compiler looks for <> include files. With most compilers, where is configurable. With the Arduino IDE, it is not.