Hii ,
I'm LVL 24 and the first questions is :
1 - How can i get more LP because when i want to kill a monster it's damage me verry hard ( 100 to 150 LP )
Is there an item to reduce it ?
2- where can i find Dogis , i search in the Dogi marchant but his has only one
where can i find it and for a good price ?

1-You need better gears, or you find them by killing moobs, or you do tmq1 until you have full set(you need lvl 25 btw to do tmq1), or you buy it from AH=Auction House=A Market.
EDIT:For the LP question, your armor/earrings need the CON stat effect to increase your MAX LP.
2-You can buy dogis on AH!

PS-The Auction House is situated in every major city of the game, you can find it in Kokkara for example.

Okk !
But The Dogis are expencive !!

1-from the event guy-bee in a floating chair something like that you get a item and when you activate that item it boosts you lp little and also rebounds 10% of the damage taken
2-buy dogis from AH

where and what is ah?

AH:AUCTION HOUSE
You can find it in all of the major cities
It looks like a sandbox with a hologram like picture above it