how do i level up in the site

Yes

FAQ baby!

Tl;dr version.
By giving away games.

What are levels, and how can I increase my level?
Levels range from 0-10, with level 0 being the default after registration, and level 10 being the highest level attainable. Levels represent a user's contributions to the community. At their core, they are calculated based on a user's contributor value. When a user creates a giveaway that's received by the winner, their contributor value and level increases. This allows the user to access additional giveaways that are restricted to higher levels. If you mouseover your level in the navigation bar, or the level on your user profile, you'll see a tooltip with the level rounded to 2 decimal places. This will give you a better idea of small increments in level, and when you're about to level up.

help yourself been asked so many times doesn't take long to find the answer https://www.steamgifts.com/discussions/subscribed/search?q=level%20up

It's a taco driven economy. Levels are a reflection of this.

It's all in the potato, dude! LOOK INTO THE POTATO!

wait...you guys are leveling up?

View attached image.