Hi and welcome to FixYa,
Most used 250s are ridden hard either as a starter bike or forced to max out playing catchup with bigger bikes. But unless abused, they tend to have longer usable life than the bigger ones. Often areas that would need your attention/check would be:
- condition/level of the engine oil. An oil change would do no harm;
- brake pads (front & rear);
- carb and tank condition, A rebuilt/clean is a wise action;
- sparkplug check/replacement. Note the color/condition of the ends of the plugs;
- valve check/adjustment;
- electrical system check which includes battery/terminals, major connectors (high amperage), regulator;
- chain and sprocket. If adjusted against the stops, might be time for a replacement of the set;
- fork oil seal.
Even if there are somethings you feel like needing work, the general judge wold be how you like riding the bike. Your body, sense of balance and riding style would dictate which if ever would need priority work/replacement/checking over.
Pls post back result(s). Good luck and Thank you for using FixYa.