how can I level up?

Click on the Help button at the top of the website: https://www.steamgifts.com/about/faq

Give any game that you most likely didn't get free yourself. When creating a giveaway it will show ** if you don't get CV for it.
Bundled games are generally good or you buy them directly.

Kill the chickens outside the village. As soon as you are level 1, you can try for the woods, but be aware of the wolves. You need level 2 for them. Starting with level 4, you can think about doing daily raids.

Do 100 push-ups, 100 upper body raises, 100 squats, and 10 km of running every day.