Timisoara Nord is the main train station in Timisoara from where all trains (including international like the one to Budapest) depart/arrive, but I don't recommend you to look for accomodation there. As well near Timisoara Est station wich is smaller used for commuter trains I think.
For the route Tm-Deva and back are several trains per day, check www.cfrcalatori.ro/en,and the journey takes around 4 hours.
For accomodation in Timisoara Liberty Sq is a good location, as well as Victoriei Sq (Piata Victoriei) and Unirii Sq. (piata Unirii) all are central and you'll find very nice hotels nearby.
Hope it helps.