Libraries (DLL modules) are shared within a process. The global variables of a library have a single instance. When you call LoadLibrary on a DLL that is already loaded, you are returned a module handle to the already loaded module. A single DLL can be loaded once only into a process.
So, it's perfectly fine for you to use LoadLibrary and then call that library's functions.
As an alternative you could use GetModuleHandle if you were sure that the library was already loaded. For example, you never need to call LoadLibrary for kernel32 since it's always loaded.