Forgotten Tales

When I bring the fragarach to the orc leader, he told me to get the missing part.then I talk to the man outside the castle,he told me to check the outpost.So where I can find the missing part and where the outpost?

Outpost is near the castle - by the water. Follow the quest dialogue, and you should be told where to get the missing part

I can't buy fish and give them to the oupost? Must go fishing?

Fader wrote:I can't buy fish and give them to the oupost? Must go fishing?

Most players catch their fish this way.
You might, be able to beg for some, if you're the begging kind.
Fish are abundant, so someone will likely help you out.
As for rods, you can buy them on map -1.1 at the shop, also known as the bank map.

I mean I can't buy fish at the store in the bank map to give to the outpost?? Cuz I see the quest say"bring 20 fresh fish"

Fader wrote:I mean I can't buy fish at the store in the bank map to give to the outpost?? Cuz I see the quest say"bring 20 fresh fish"

In which language are you playing? The quest requires 20 RARE fish. They cannot be bought in shops. You have to fish them, or to ask players if they can sell you some, or give you some for free

Thanks and where I can get a mithril pick axe?

Fader wrote:Thanks and where I can get a mithril pick axe?

It's a craftable item. You need a clan crafter building, or a private house in order to craft one. You also need 10 mithril ingots, a meteor stone, a magic trunk and A LOT of luck, because the success chance is VERY low.
Otherwise, you can buy one from players, or get one from chests in map 4.0 (and its underground) but your level is too low for that so far