Go on your trip. If the light comes on and the engine is still running fine, don't panic.
In most cases, the CEL means the computer has found something out of spec in the emissions control system and has turned on the light to let you know to have the system scanned to determine the cause of the indication.
At 77K miles, you have several sensors and components that may be reaching the end of useful life. Most common are the oxygen sensors. The CEL can also be caused by something as simple as a fuel cap that was not installed properly.
AutoZone and Advance Auto Parts are among chain stores that will, in most areas, read your computer codes for free. If you take advantage of this service, be certain to record the exact codes. Post them here for discussion and help in diagnosing the cause of the code.
Steve
