as a player/character, or in real life?
When I read the question, I assumed I was playing a character in a game. If the GM hands me that, I quickly gather my friends and go exploring.
In real life, to do anything quickly would pretty much require that the ship's computer(s) are fluent in English, or can and will learn it really quickly; or the ship's controls and gauges are ridiculously simple and handling is really forgiving.
In real life, with an English-fluent computer, I have to find out the crew's purpose and circumstance first. If they are on Earth for hostile purposes, that has to be dealt with. If the pilot is just here to collect floral samples, and has just died of a rattlesnake bite, then it's time to have fun with his ship.
First, I am sure I would be freaking out that he was human. Actually, if he was human, I wouldn't believe it was extraterrestrial. If it wasn't human, I would be freaking that the ship was so perfect for humans.
Assuming it wasn't human, I guess I'd use sensors to see if I had anything or anyone scary headed in my direction. If it had any stealth capability, I would use it. Then I'd see about water and food, perhaps hydroponics. Even if the alien breathes an atmosphere similar to ours, it's not bloody likely its food would be edible, let alone sufficient, for humans.
I have a couple of friends whom I would trust to not rat me out, and who might want to go along. I'd ask, then I'd go. I'd disable my comms receivers, so no one could try to hack into the ship's computer(s). I would do ball of twine surveys of the sun and all of the planets and their moons, sending the data back to Earth. Then I'm off to the most promising looking system in the navigational database.
If I am worried about getting jumped by cops, military, or whomever - likely, if there is no stealth capability - then I head for L5, or the far side of the moon, or Mars, NOT EARTH ORBIT. I do not want to be in range of anything hostile. Constant acceleration is great, but 2G ain't squat compared to an incoming missile.
Really, if there is no stealth capability, I won't be able to stockpile enough food aboard to make this work. Well, if there is a Star Trek food console that can create any food, and a medical computer or database to tell it what I can survive on, then I could take off immediately, if need be, and survive indefinitely.