Answer:
Similarities:
The U.S. and Europe territory are almost entirely within non-tropical territory, above the Tropic of Cancer.
The U.S. and Europe both have large plains in their territory. The U.S. has the Midwest plains, and Europe has the northern European Plain.
The U.S. and Europe also have mountain ranges. Some of them young, like the Alps in Europe or the Rocky Mountains in the U.S., while others are very old Mountain Ranges, like the Appalachian Mountains in the U.S., or the Scandinavian Mountains in Europe.
Differences:
Europe's latitude is much higher than the latitude of the United States, on average. Madrid, one of the southernmost European capitals, is at the same latitude as New York City, while Florida is at the same latitude as Morocco and Western Sahara, in Africa.
Europe has a more complex coastline, with many smaller peninsulas (Europe itself is a peninsula), inner seas, inlets, and so on. The coasts of the United States, especially the West Coast, is much more straightforward.
The United States has a large area that has either a subtropical or even tropical climate (South Florida). Europe lacks either of the two because of latitude.
