Back in the day that I needed some shelter next to the bus I found out through many tries
the easiest thing to do.
I used a silver 10X18 tarp. some 1/4" nylon rope to go through the eyes and around the edges.
Then fastened 2 Eye-Bolts up on the drip rail spaced so that I could run the nylon rope through
each one to pull the tarp up onto the side of the bus. Then using short bungee cords I would attach
the tarp to the drip rail so it wouldn't flap around.
Then I just rigged up two or three poles out of conduit 3/4" and 1/2" that had holes drilled through them
and slid inside each other. Using a clip to lock them into the right postion.
A couple of tent stakes and some more rope to tie the poles to.
Use plenty of bungee cords and the temporary awning can flex and flap so it won't tear anything up. I had a lot
of rain when I was using these types of awnings and they would fill up with water. The bungee's and nylon rope
would give enough for it to dump the water if It got too heavy or a sudden wind came up.
Everything folds up and with only a couple of poles to stash somewhere it was pretty easy.
I now have a 10X10 pop-up shelter that folds up. It has it's drawbacks but is pretty stable
if you give it something to hang onto. ( bungee's) work very good for holding stuff down.
I always buy bungee's and duct tape if I see a good deal, You can never have enough....