Buying my first truck

As the title says, I am planning on purchasing a used truck. It is a 2011 ram 1500 outdoorsman with 50k miles for 22k. I was wondering if there were any wise readers here who could give me some tips on what to look for when I take the test drive and look under the vehicle. I'm planning on bringing my friend who is more mechanically inclined than myself but any extra tips would be more than welcome. Also, if you have any tips on how to care for it and perhaps first upgrades. Thank you so much in advance.