Do you get a gold when playing Trading Post?
No, you do not receive any coins. It is indicating a discount. You only pay {1} Coin instead of the normal {2} from the neighbor in the direction to which the arrow points. You can contrast this with the Tavern card.
7-Wonder's rule book (page 12).

Tavern Icon - the card is worth the amount of coins pictured, the coins are taken from the bank only once, when the card is played.
Trading Post Icon - starting on the turn following the one in which this building was constructed, the player purchases raw materials from the neighboring city indicated by the arrow for 1 coin instead of 2.
Clarification for the Eastern Trading Post, the Western Trading Post and the Marketplace: arrows show to which neighboring city or cities to which the discount applies.