Depend what you have in Package. But one thing sure, to use any component from a package you need to use a DOT Notation. Let's say you have a package named mypack and have one procedure named myproc .. To execute this Procedure you can run like

Exec mypack.myproc;

or

Begin
mypack.myproc;
end;
/

Hope this will help.

If you have any parameters for those functions and procedures, you need to give those Param as well just like stand alone Procs and Functions.

Thanks