I need a really cheap lean to or covered work space against a fence

How about using pallets which you can pick up free or low cost? Here are a couple links to consider.

http://m.wikihow.com/Add-a-Lean-To-Onto-a-Shed

https://youtu.be/hGtxSTo6Pow

Use pallets(free) to make a hutch type table and use additional pallet boards to create a roof coming off the top and perhaps cover it with left over pieces of siding to create a water proof roof you can work under when it rains. With the hutch type you could have plenty of shelves above the work bench and even below if you want.

Think about hanging a sail sheet shade. Maybe building a support for a bamboo shade? A couple of prefab fence sections?

Ooops! Another thought: pop up tent or similar. Gazebo tents are all on sale now.

Thank you all so much!

Get some pallets and remake them into your lean-to. Cheap and easy.

thank you