How do I get my pictures to look like this? Do I have to increase the brightness?
Thank you and best regards!

Sorry but for some reason I can't post the actually picture but here's the link

CLICK HERE FOR PICTURE

By the looks of it looks like they used an external flash unit probably on a white umbrella, then they desaturated it a bit in photoshop

I'm not 100% sure I'm right though

Thanks for your reply! Would that be the same case for this photo? Not the white umbrella part but the desaturation part
CLICK HERE

the second pic; the figure is just extremely darker bc of the bright sunlight behind her.

that first picture is definitely desaturated, and the tint has also been changed a bit. If you have photoshop or lightroom, you could make those effects.