Hi Abilene. Sorry, I'm not familiar with any particular problem with the C250 starters, so I'm afraid it'll need some diagnosis.
1) Are your lights working OK when the engine isn't running? If not, then it's likely that your main fuse has blown, and that the bike is running off of the alternator, rather than the battery. You can just replace the fuse (it should be under the seat, near to the battery +ve terminal) and away you go.
2) Find the starter motor casing. I don't know exactly where it's placed on your engine, but it should be a fat cylinder on top of the crankcase. Find the terminals on it. Check them for corrosion, or loose wires.
3) OK, so the wiring and terminals seem sound, and so you've got lights, but no starter. It's time to buy yourself a cheap multimeter (or a 12v voltage tester), for a few $$$. A multimeter is a great investment, and really quite easy to use - YouTube has plenty of "how to use a multimeter" instructionals.
You'll want to use it to check for voltage at the following places:
3.1) Across the battery terminals. This is a double check that it's not just a dead battery, and to check that you're using the meter correctly. You should see 12.5V or so.
3.2) Across the starter terminals when you press the starter button. If there's voltage across the terminals but the starter doesn't turn, then the fault is internal to the starter and it needs to be stripped or replaced.
3.3) If there's no voltage across the starter terminals, then you'll have to trace the wiring back and see if you can find the problem. Next port of call is the starter switch itself. With the switch not pressed, there should be 12V between one of the starter switch terminals and earth (the bike's chassis). If there's no voltage at either switch terminal, then the wiring between the battery and the starter switch is faulty - you'll just have to trace it back to find the break.
3.4) With the starter switch pressed, you should have 12V (between the terminal and earth) at both switch terminals. Alternatively, use the continuity (aka diode) mode on the multimeter to check for continuity across the starter switch terminals with the switch pressed. If there's only voltage at 1 terminal (and no continuity between them) then the switch is faulty and needs stripped or replaced.
3.5) If the voltage at the switch terminals seems good, then you'll have to trace the wiring from there to the starter motor to see if you can find a break in it.
I know that's not the answer that you want to hear, and electrics can seem pretty daunting at first, especially if you don't have a wiring diagram. But it's either that, or take it to a mechanic and pay him or her to go through the same process. I do hope it's just a simple wiring fault and that you find and fix it easily.