>>2827775 (OP)>four hourdoesn't mean anything. Speeds vary massively between people and terrain, for example, I do 7kmh fresh with no weight, and 2-3kmh tired with full pack.
>what to take for 500m elevationDepends on the area (climate) and terrain. As a general rule, dress so you're slightly cold when starting, else you'll sweat terribly. For longer hikes, you'd bring a jacket to cover up during breaks, but 4h should be possible without breaks, to.
Other than that:
>suitable footwearFor such a short hike, and on a maintained trail, don't bother with boots. Just wear whatever is comfy. Personally, I'd use flat-soled running shoes (cheap feiyue) since those are what I have, but any shoe will work. Just don't take any you don't want scuffed or scratched. Wear wool socks if you have any, since they remove the sweat more efficiently, meaning your skin won't soften as quickly. But again, 4h is short, so it doesn't matter much.
>waterbring enough. For me (~90kg, sweating lots) that'd be 1,5-2l. I usually bring ~1l + a filter so I don't have to switch canteens midhike, bcs. taking off the pack sucks when you're sweaty.
>sun protectionWear a hat, preferably with a wide brim. Keeps the sun out, and also keeps branches, spidernets etc away from your eyes.
>fakbring some bandaids at least, a few bandages if you have them anyways. Unlikely that you'll need them, but better to be prepared in case you stumble and skin a knee, or twist an ankle.
>comms, navigationbring your phone, and install an offline navigation app like osmand just in case. And if all else should fail, follow water - go downhill until you find a stream, then follow that downstream until you see a street or town.