There are two shots of train journeys taken by Kelly and Joanne. One is in an Electrostar class train and the other in a "Networker" Class 365. In both cases the internal shots are of the much older (Class 421?) diesel/slam-door trains.
There is no Stagecoach bus route from Brighton Station to Brighton beach. To make this journey by bus Kelly and Joanne would have had to get a Brighton & Hove bus.
For the exterior shot and interior scenes, the sun is shining from the wrong side for a morning southbound train journey.