Help me choose a bike!!!

so im looking for a new bike. i dont have much money, if i can i only want to spend around 500 new or used.
ill be using it mostly for just cruising around town to friends house's and stuff, ill probably never ride over about 10 miles, 15 would be the absoute max, i like to kinda goof around and like "jib" stuff, though im not great at biking. i also want to use if for some mtn biking, there are some trails around here that are pretty fun, nothing really hard or anything, its usually pretty easy with maybe 1 tricky spot on the whole trail.
there is also a bmx track close by, its not great, but we sometimes just go there and mess around on the jumps and stuff. there is also a mtn bike park somewhat close by with lots of those wooden tracks (dont know what they are called) and stuff like that.
so im not some really serious biker or anything, but i do like a bike that can handle stuff cause i can be somewhat rough with them.
and i dont like big bikes, i like my bikes a little smaller than normal, i like to have quite a bit of control.

i was thinking a hardtail dirt jumping bike, it would be small simple, tough, cheap, and be fun for messing around on, im just not sure how it would do on mtb trails its pretty much a bmx but with front suspension, though with my friends sucking at biking so bad i doubt id be left behind.
i dont know about getting a full suspension, cause for around 500 its probably gonna be pretty shitty.
a hardtail cross country bike would probably work, but i like the whole bmx type setup of dirt jumping bikes better. though the cross country would be a little better for cruising long distances, and maybe a little better for trails. but they arent as tough.

and do they make dirt jumping bikes with gears?