Loading 35mm film properly

[thedogspants]

Heya,
I am new to PR, and thought asking a simple question would show how much of a "newb" I am.
On the first picture of every roll, almost half of the picture is white. When I first noticed this, I thought I was loading the film wrong. So to make sure that it loaded correctly, I always did it in a room with a safety light. It still turns out with the white block. The picture below is from the first roll in my Dads Olympus OM10.

Can anybody lend me some beginner tips on getting the first picture to actually turn out? Whenever I load film now I usually take a "scrap photo" because I know that it isn't going to be a full picture.

Thank you,
tdp