Hi Itay sorry I am late,

Here are a couple of tips to help you out through your 24 hours in Amman.

You can visit the Citadel, Roman Theatre and Forum. For some good historical sightseeing.

You can also walk through some very interesting markets: JARA Flea Market(Fawzy Ma'louf Street )  taking place each Friday from 10 am to 9 pm but I would check that before going . The Jordan River Foundation shop is a wonderful showcase of traditional handicraft. Right in downtown Amman next to the amfi theater there is a lovely fruit and vegetable market. you can also go on a day tour to the city of  Jarash.

Have fun,