Sorry, I saw "designspark," but was thinking of SparkFun. I am not familiar with that piece of software per se, but I suspect you make a polygon around the area of the pour, assign it a rank along with setting some other variables, name it, and then pour. You can have overlapping polygons and use different ranks. That is a powerful tool. Thus, your power net and ground net can generally be taken care of with pours, but with different ranks, on the same side. As Ron says, if you are using through hole devices, connecting pours on different sides is not really a problem. For DIY, it is also easy to add your own vias, and just use a wire soldered to both sides.
John