Shops, and connectivity

[monkey4sale]

Ok, im just trying to make a practice MMO

Is there a way for people to connect to my computer without portforwarding?

And now to the shops part: Alright i found out how to set the shop up, but is there a way to make the npc spawn in a certain spot? and for some reason the only item i have for sale in the shop doesnt appear in the picture, if i select the square it syas it is their but i cant select it