How do the points work? Especially with the giveaways? And how do you level Up?

https://www.steamgifts.com/about/faq
https://www.steamgifts.com/about/guidelines

"How do I receive or earn more points (P)?
Every user on the site is given an equal number of points. You will receive 6 points every 15 minutes."

You level up by giving away games.
https://www.steamgifts.com/discussions/subscribed/search?q=level%20up

https://www.steamgifts.com/about/faq

Press ctrl + F and write points in the search box on that page.

You also might want to click the "Edit" button in the upper right and move your thread to a better fitting forum category like for example:

https://www.steamgifts.com/discussions/help