This scenario is set in a Roman down at the Eastern part of Briton, at the foothills of several Welsh mountain ranges along the river Usk. While you can grow many crops, the land is rocky and not any good for growing wheat. The Celts have recently been subdued, but you can expect them to visit you from time-to-time.
The empire is going through a time of great expansion. Right now there is a good demand for goods, so export income is good, but the over-expansion is expected to cause an over-supply of goods and a lowering of prices your trading cities will be willing to pay for your goods, so don't forget to make your city attractive to wealthy patricians and the taxes they will provide.