prefold diaper help

So I just bought some prefolds and thirsties duo wraps. I ended up getting regular size prefolds. I put one on for the first time and for some reason I could not get the snappi to go on right. When I went to change him it wasn't even attached to the diaper anymore. He was in it for maybe an hour and a half and the entire pre fold was soaked, is this normal for prefolds? He also had a slight diaper rash just from one wear. Another question is there a better fold for boys?