well if you're new to jumping, then i'd try to find a small hill somewhere on the property to work off of? if you have a hill on the property, then get some dirt and build it up on the hill. make it as big as you want, just make sure the transition is smooth-you don't want to abruptly change directions from going runway to jumpface.
if the hill is big enough, you might try a ski jump. find the halfway point of the hill, and build the jump there so that you are jumping down the hill, not up. make sure that you have enough hill to land on though, because if you jump to high, you could flatland it and bottom out.
another way to build a jump on a hill is to make a step-up, but you need a pretty big hill and more dirt if available. make the jump at the very bottom so that you are jumping up the hill and will land at or somewhere near the top.
if you don't have a hill at all, then you will need a whole lot of dirt. it will also be difficult if you are only using shovels. but if you want to try:
i'd suggest a take off two or three feet high (though you may have to build it up to 4 feet for when you pack it down). maybe somewhere from 40 degrees to 50 degrees. again, transition is important. start the bottom of the landing maybe 7 or 8 feet away from the take-off and build it up until it is about 4 feet from the take off. height of the landing should be maybe two feet high four feet away from the takeoff and gradually slope it down 7 or 8 feet.
you may also wish to make the landing farther and farther away as you begin to hit the jump harder and harder. you are also going to hold the throttle steadily and maybe blip it at the lip of the jump to prevent nose diving.
this way requires alot of dirt though.