How can I cover up a 6 ft fence with plants?

Clematis and climbing hydrangea are 2 plants that like shade, Doug.

I love Ann's suggestion of Clematis. They climb and grow rather quickly. We are in zone 7b and it is a plant that does well here. I like what you have done so far!

Really depends where you live but here are some suggestions FILL IT IN WITH FLOWERS TO BRING YOUR EYES DOWN AWAY FROM FENCING--https://www.diynetwork.com/how-to/outdoors/gardening/10-best-perennials-for-shade MORE FLOWERS https://savvygardening.com/shade-loving-perennial-flowers/ ACTUALLY COVERING FENCING https://www.fromhousetohome.com/garden/flowering-vines-for-shade/ MORE https://www.youtube.com/watch?v=FIctAgObVk0

You could put up plant hanger brackets and get some nice spider plants, photos or other draping plants. Make sure you have somewhere to put them in the house during the winter, they do really well in the house without a lot of light and you will be able to put them back outside in the spring and also start new plants with the spider plant babies and cuts from the long tendrils from the pothos for more plants to put out.

Sweet pea vine should be happy there. And you don't have to winterize it

I would use vines such as ivy.

Would you want to create a hedge in front of the fence to help? If so, Viburnum is a great plant to use in partial shade!