Eh, most females can take two fingers in an inverted V-salute position, use them to spread the labia and pull upward and back a bit, which'll position the urinary opening such that the stream'll arc forward. This requires practice and isn't really very helpful for FTM's who want to use urinals, 'cause you pretty much must drop your trousers down past your butt for it to work right.
Simplest, cheapest, thing is to take the plastic lid off a plastic cottage-cheese or yoghurt container, cut the rim off it so it's just a smooth circle of plastic, cut a flat edge on one side, fold the thing in half into a V-trough and hold it in place just under your urethral opening. Try to, uh, moderate the stream, if it's too forceful you'll make a mess.
There are commercially made devices that work more or less the same, available from camping stores. And other ways to improvise. Medicine spoons. Or once, a friend of mine (a bio-male) was walking down the street and somebody peed on him from on top of a building. He ran up to the roof of said building in a rage and discovered two very pretty girls up there, peeing on men through the big straws you get with fast-food milkshakes. He was so tickled by this that he had to get them more drinks so they could pee on more men.
Since peeing standing up isn't really your issue, you just want to pee neatly while camping, you might find a female bed-urinal adequate or better. You can get 'em from drugstores, and I think you can even use one in the car.
