What characteristics are common in Gothic type churches?
Gothic church architecture came after the Romanesque. Where the Romanesque style was heavy the architects of Gothic churches wanted to create a feeling of soaring to the heavens. The ceilings are very high with the supporting pillars rising up to support the arches of the roof. On the outside Gothic churches were characterized by tall spires and the flying butress that helped to support the structure from the outside. Gothic churches made use of many statues of the saints on the outside and by lookin carefully one can spot gargoyles that represented imaginary beings and animals, mostly frightening. all windows let in light from the outside and many of the windows made beautiful use of stained glass depicting scenes from the Bible. Your best bet is to look at photos of the classic churches of Paris (Notre Dame) and Milan.
