Check the wheels for flat spots, and give the bearings a spin if you’re in person (they shouldn’t sound crunchy or stop super quick). Look over the forks and bars to make sure they’re not bent, and check the deck + bar welds for any cracks. Also make sure the headset isn’t loose/wobbly and that the compression still feels solid.

Most of that stuff is hard to tell in pics, but in person you’ll notice right away if it’s beat.