Regarding awning installation. You have a couple choices given that it's such a small trailer.
First, you could go with a bag awning. This will be the cheapest route. You roll the fabric up and it stores in a zippered bag on the side of the trailer. Depending on the bag size, you may run into problems with it clearing the entry door when in the bag though. To set up, you unroll it, prop it up with loose, adjustable poles, and then stake it out with ropes. This is a pretty light duty awning.
Second, you could go with an armless crankout awning. Sort of like a self contained box, you crank this out and it's like a scissor. Nothing goes to the ground, so you can walk around it easily. You must be prepared to put it away in wind or heavy rain though. These type of awnings are typically used in smaller form over the entry door of a motorhome where the patio awning doesn't quite reach. Not sure how these are price wise though.
The last option is the most traditional, a standard roll out patio awning. The fabric rolls up on a spring loaded tube with arms that attach to the trailer. When rolled out, secondary arms fold out to tighten the fabric and make it sturdier for light wind and rain. You will still want to tilt this kind to one side to allow heavy rain to drain off though. The advantage here is you can have the awning fully self contained without relying on attaching to the ground, even though you can put the arms out on the ground.
Even though Sunlines didn't come from the factory at that time with awnings, the #3 style was often the type chosen as an aftermarket dealer accessory. Starting in the mid '90s, Sunline installed this style on every trailer that left the factory. I would definitely say it's the most common type on RVs in general now too. The two common brands of awnings, Carefree of Colorado and A&E by Dometic, both make a small enough awning for your trailer (I think the smallest is about 8'), but most dealers won't stock something this small and you'll have to special order it. With the way RVs have grown over the years, the most common awnings now are in the 19 and 21' range, so finding a used awning in such a special size for your trailer will be nearly impossible.
When ordering an awning, they will (or should) give you the option of a metal wrap. This is a series of metal pieces hinged together at the top of the fabric that cover the entire roll of fabric when rolled up. It's part of the material, so you don't have to do anything special when using the awning. The advantage to it is that it keeps the sun off of your awning fabric, as well as protects it from tree branches when driving. Awning fabric often gets very sun beat on the top of the roll when rolled up, thus making it very brittle and small pin holes do develop. The metal wrap is a small price to pay to get a few more years out of fabric, especially in Texas.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR