I would not trust a dealer to do ANYTHING correctly. It's your life on the line, get down on your hands and knees and check EVERYTHING yourself.

After 15 or so new bikes I can attest to multiple **** ups by dealers ... even on very expensive bikes. IE:
New KTM Duke ll ... Front caliper bolt missing, other one loose.
New VTR1000 Honda ... Steering stem top nut finger tight, plastic body work loose, axle nut loose!! Tires inflated to 50 PSI
TDM850 ... levers and handlebars loose, tool kit missing, low tires.
Vstrom DL1000 ... over inflated tires to 45 PSI

Always go over your new bike with a few wrenches, allens and Phillips ... grab, feel and pull on everything to make sure it's tight and OK. Double check routing of things like cables, hoses, Wire looms, battery installation, check lighting, make sure seat is installed correctly. Double check axle nuts, chain slack, brake caliper bolts, handlebars bolts.

Check that all handlebar switches are positioned correctly and tight. Set up bars, controls and levers to suit YOU ... not the guy who set up the bike.

Tire Pressures are frequently screwed up or ignored. forget what it says on tire sidewall (that is MAX pressure under MAX load). Use what the bike manufacturer recommends in the owners manual. Sit down, read it cover to cover. You'd be surprised what you might learn.

Most new bikes come with a factory dry lube on the new chain. This is really only to prevent rust during transit, not really a chain lube.

Use a bit of diesel and clean it all off, wipe clean ... then apply chain lube or 90 wt. gear oil. Wipe down and clean everyday, re-oil daily, more in rain.

XR250's oil level should be checked when engine (Dry sump system) is HOT ... not warm, but HOT. When cold, it will always read low. In this case many owners OVER FILL engine. NOT GOOD.

Once the engine is HOT ... turn off, wait just one minute, now check level with bike on level ground, following owners manual method. Add if needed. If it shows way over filled, siphon some off. Over filling causes a variety of problems ... some serious.

Your new bike may use some oil in the first 2000 miles. So check level twice day until oil use stabilizes. Then, check just once a day when bike is HOT. After long highway runs at high speed you may find OIL in your air box, in your air filter.
This could indicate oil is over filled ... but also can happen on brand new engine. So don't panic. Just make sure oil is FULL ... but not over filled! Wring oil out of air filter, clean up air box. It will go away soon enough.

Ride Safe!