How i gain P?

Just wait. Every time somebody gives away something, that´ll give you some P.

Read the FAQ and don't double-post

keep calm and just relax

The point system is designed to prevent users from entering for every single giveaway. This lowers the overall number of entries, and provides everyone with better odds of winning games they're interested in playing. New users start out with 25P. Every time anyone submits a game, every member of the site, excluding the giveaway creator, receives 5 percent of that gifts value (in USD) in points. For example, if a $50 gift is created, every user on the site receives 2.5 points. And, if a $20 gift is created, everyone would receive 1 point. These points can then be spent on entering giveaways.
1P = $1 - When entering a giveaway, 1P is equal to $1. If you're entering for a chance to win a game valued at $20, you'll spend 20 points. If at anytime you decide to remove your entry while the giveaway is open, those points will be returned.
The maximum number of points that can be banked is 300. This is to prevent users from stocking up on points while being away for long periods of time.

As others indicated, you just need to wait. You get some points when new giveaways are created, which seems to happen pretty frequently. It won't take very long to save up points. I've only been here for a week or so, and even after entering 100-something giveaways, I'm currently at like 278 points (and 300 is the max). Hang in there, the points will come.

by readin the faq

To gain more P, drink more water.

go to sleep and u'll see they magically appear

If you PM Lokonopa, you will get over 9000 points.

Drink more water. You will get more P. Use wisely.

by being patient

wait and sleep