Most likely, as is the case with other fasteners, they are aluminum Robertson head (square drive; marvelous invention, I use them exclusively in everything from wood working to metal working; McFeely's carries a full line of them) aluminum screws with a white baked on finish or heavy duty Phillips head sheet metal screws; very few machine screws used on these trailers.
You can price out the parts you'll need, but, you may find, if you follow sales, that you can replace the whole awning for the same or less. Just another option... Quite often, the individual parts are more expensive than the sum of all the parts.
My 2 cents, your mileage may vary...
2 Cats; J-Lo and Ragamuffin :R
2014 Thor Tuscany 40RX DP
2011 Ram 2500 Longhorn CTD HO
2011 Keystone Cougar 318SAB (now gone)
2008 FunFinder X 210WBS (Sadly gone)