If you are playing in the remake, the Town Hall and Siege Workshop have been removed and replaced by the marketplace (although I believe the Market is only available in Multiplayer as I haven't seen it in Singleplayer thus far).
At least how you wrote is, it´s not correct

The Martketplace was added addtionaly, but its not been "replaced by the marketplace". However you are right, that the marketplace is disabled in the original campaigns !not in sp missions in general!
omg... if that the case.. how am I going to win the mission? there 2 AI with iron armor troopers.. with leather armor troops.. the chance of winning is very very slim.. sigh..
TPR 09 is a very easy mission, sorry to say that

but it really is.
Some tips:
+ Try to make really fast leather production and kill the village left of your base (the brown leather base). In original kam it was possible to kill them in the beginning with the catapults, but even now you can pretty fast kill those brown guys with 10 bowmen and maybe 6 lances.
+You are able to build towers here, so if you aren´t able to make fast a big army, you can go rush roads to the north west. Take the fish that is in the sea while on the way and rush nearly until the bridge. There you place some towers. Now it shouldn´t be too hard
Have fun
EDIT: I agree that the townhall should be avaible in this mission, unless you have no iron and can spam barbs and horses fast with it, but the Remake team haven´t found any proper way to implement it in a balanced way, same with catapults and balistas. Some people think, they can´t be implemented for Singleplayer only, so they have no solution how to bring them into mp, that the balance of units there, will be still good.