What SilverSage said. In fact, I think it is illegal for a seller (be it private or a dealership) to deny you the opportunity to take the truck to a mechanic of your choice for a pre-purchase inspection before purchase. If they refuse, walk away because you can bet there's a reason. You will have to pay for the inspection, but it is worth every penny! When I was looking for a car, I test drove several older Mustangs. One I really liked a lot, it was a GT, low mileage for the age and looked pristine. I noticed the gears were a bit 'sticky' on the test drive (which the salesman blamed on ME being a woman

) and that it just kind of drove 'rough'. My mechanic took one look and said the entire transmission was shot and told me flat out "do not buy this car"! Despite only having 60K some odd miles, whomever owned it before drove it into the ground. I was out whatever the inspection cost, but at least I wasn't out thousands of dollars for the car PLUS the repairs and kept looking! The one I ended up buying had 90K+ miles but the mechanic said it appeared well maintained and after a little over 10 years owning it, I have had no significant issues with it beyond a few relatively minor expected 'old car' issues. Do not assume a vehicle in good cosmetic condition that isn't billowing smoke and making clunking noises is "ok". PAY THE MECHANIC AND SAVE YOURSELF A LOT OF MONEY AND GREIF!
Be sure you have insurance before signing the papers or you won't legally be able to drive it away (if a private purchase. A dealership won't even let you sign the paperwork without proof of insurance). I would also strongly recommend not just getting state minimum. We got screwed when my husbands car got stolen and trashed out by meth heads because it was on state minimum and not insured against theft. NEVER AGAIN!
If you are out of practice driving or have simply never driven a huge vehicle before or are getting a stick and are out of practice with that, plot a route home that sticks to back roads. Seriously, it's not safe to hit the highway under those conditions. Give it a couple days to get a feel for the truck/driving it. I've driven everything for XL SUV's and trucks (and a few Uhauls!) to 2 seater sports cars. It's a massive difference in handling a large truck (especially if you're getting an extended bed, or a dually) to a car or even a smaller SUV.
We pay cash for cars, so I have no advice for financing but if paying cash (which I always recommend since I am anti-debt), budget appropriately to allow at least $500-$800 above and beyond purchase price for some initial repairs virtually all used vehicles will need. Little things like an xyz-mile tune up that wasn't done, oil change/fluids top off, brakes, tires, windshield wipers etc... aren't necessarily a reason not to buy a vehicle but do add up quickly and you want to get them all knocked out ASAP after purchase. You should also begin to budget monthly for maintenance on the vehicle. We set aside $50/month per car and just let it build up. That way you have maintenance like oil changes and tune ups covered but also don't take such a major hit if a big repair comes up.
Good luck on purchasing your first car! Exciting times
