Alien spaceships present a whole host of problems. Fictional extraterrestrials range from tentacle horror shows to ephemeral energy beings, so there are no guarantees you'll even be able to climb aboard, much less take the ship for a test-drive.
Just consider your own ill-gotten starship. Does it lack a physical cockpit or breathable atmosphere? Is the pilot's seat made for square buttocks? If the ship designers were alien, don't expect a human-friendly layout.
Fortunately, a great many fictional aliens are morphologically similar to human beings. Many even appear to speak English! So, you might just be in luck. Jeff Goldblum and Will Smith had no problem commandeering an alien spaceship in "Independence Day," though other vessels such as the "Robotech" SDF-1 Macross required a decade's worth of research and retrofitting.
If you're lucky, the spaceship you score will host a benevolent robotic pilot to do all the work for you. The Trimaxian Drone Ship in "Flight of the Navigator" is a classic example of this. Sure, it might store star charts in your brain or ruin your life with time dilation, but that's all water under the bridge when it becomes your BFF.
Sometimes a ship's artificial intelligence (AI) will even manifest itself in a physical body, such as the demilitarized warship Xenophobe in Iain M. Banks' "Use of Weapons," which takes the form of an adorable catlike creature. When traveling aboard the Xenophobe, cuddling with said creature is highly encouraged.
Still, not every spaceship AI yearns for friendship. A bot like HAL 9000 from "2001: A Space Odyssey" might try to blow you out an airlock.
Other pilot AIs want to be much more -- "spaceships with benefits" if you will. Ship-piloting AIs in both "Futurama" and "Mass Effect 3" have fallen in love with their crew members, generally with problematic results. Sex with a spaceship may sound fun at first but don't give into the temptation. Stick to cuddles.