Owen
Glad to hear you are joining the brotherhood. The CB250 is bullet proof you should get years out of it. The key to keeping it healthy is change the oil and filter regularly. New oil is cheap insurance for your motor.
My informed source has just told me the seat on the CB is removed after undoing the lock with the key (helmet lock), then using the release lever near the lock. I have not done this myself, but may in the near future as I have just started looking for a bike for my son. The CB is at the top of the list as it is a great learner bike.
I am not sure what the current learner set up in NSW is now, but the pre learner course should give you some great tips on how to maintain your bike. Some of them are;
a pre ride check of brakes, tyres, lights, fluid leaks and anything falling off.
Weekly checks of tyre pressures and tread, chain tension, lube, batteries, fluid levels, brake pad wear. To name a few.
I did the NSW pre learner course many years ago as part of my instructors training. Even after 20 years of riding I still learnt a couple of new things and reinforced many old things. I work with Stay Upright in QLD now doing QRide and advanced courses. The pleasure I get get from helping introduce new people to riding is immense. I will never get tired of seeing the ear to ear grins that all of the students have at the end of a course.
Enjoy your riding and take care out on the road.
Craig