Support for your device is all but gone, to be honest. A majority of apps support the latest iOS versions and if your device can no longer be updated then you are limited.
As @Just_Me_D stated, you're not going to find much. My son has an iPad 2 that barely works so I can't imagine a gen 1 being able to do much these days. Your best bet is to purchase a new iPad. You should be able to find plenty of good deals on a used iPad Air.