The chain lubing I would definitely recommend doing. Also would not leave that to a mileage gauge either. Chain maintenance will vary on usage, weather and other sum such. Oil change really isn’t that hard, biggest step is getting over the fear of doing it. Find an online forum and see if someone has done a write up on it.
If its a Kawi 250 try here! and just find your way to the sport bike section or the how to sections.