You can't find screws because there aren't any. Those are rivets (I know this because I went through the exact same thing).
To remove, I used a flat chisel and hammer to remove the rivets, then the awning slides off towards the front.
Upon replacement, you can use pop rivets or screws and plastic mollies (spelling?) - anything that will go through the holes and expand on the other side.
I would agree completely that screws make more sense, but....well....
Best of luck.
2008 Journey 39Z Cummins 350 ISB 6.7L
2006 Honda CR-V LX Tow