If it is vinyl you can use about anything short of battery acid (it is really tough stuff), but I would stick with the usual household cleaners and degreasers. No abrasive cleaners, though. Pine tree sap can be removed with isopropyl alcohol.
Acrylic fabric is an entirely different matter. Rinsing it well and using a light duty detergent (such as car wash detergent) is about all that is recommended. Unfortunately, that won't remove any serious dirt that has sunk into the weave of the fabric and awnings often get a lot of that from overhead tree branches. I've successfully used Oxy-Clean on such nasty dirt and "scrubbed" with a light brush, the same brush I use to wash the sides of the RV. But if you do too much scrubbing or use too strong a detergent, you WILL remove the waterproofing and have to re-coat it. That's not a terribly difficult job - you buy several cans of waterproofing spray designed for synthetic fabrics (most outdoor stores have it) and spray it liberally. Been there and done that - works fine.