Call is_user_logged_in

Dear sir or madam !
I am deverlop wordpress, and of course wordpress nearly new to me !
Okey ! My problem is :

When i create a new file in root of wordpress, for example: album.php and the head of thousand code is : include ( wp-load.php).

But i found that some function call in error, and this case is : is_user_logged_in() and some function checking user loggin don’t run.
So what i have to do ?

Thanks for help !