ok first space is like a vacuum there is no gas or oxygen for u too breathe if u actually went to outerspace without a helmet u would suffocate then i think ur body explode because all of the oxygen in ur body would would be used up
There is radiation in space, from the sun and other sources. However, without a space suit you obviously wouldn't live long enough to get a sunburn, let alone radiation poisoning. However, IF your space suit didn't provide any radiation shielding, it would be a problem. And during "solar flares" when the sun puts out a sudden burst of heavy radiation, even the astronauts in their space suits have to stay inside and preferably have extra shielding in the space vehicle or station.
Aside from having nothing to breathe, you would burn on the sun side and freeze on the shade side. Our atmosphere is the only thing that keeps us from burning during the day and freezing at night. Our own moon gets hot enough to cook pancakes on during its day and cold enough to make a rubber ball as brittle as glass during its night.