Great Northern Wall & Squire Zachery?

Can someone please explain in detail where this is?

I went all along what I thought was the norther wall but that ended up just being a wall that bordered with the Breach.

Sorry if this is a major noob question, but that's what I am: a n00b!

Go inside Ascalon City and follow the green arrow to the zone point, which will be up the stairs from Warmaster Tydus.

Yes, after speaking with Tydus and getting the quest, go UP the stairs (only one set going up). Hang a right and follow the path to the next area. That's the physical directions, but I think there should be a green arrow for that one like FF said.