Backyard wedding are beautiful! here is some inspiration :)
Here are a few more for you. Have you selected your wedding colors?
I love this..you can DIY this sign for outside the tent area to let guests know where everything is.
Here are some with uplighting and other lights
A few more from the same website
You could use the draping in the tent.
Here is a smaller tent that could possibly be used as a sweetheart table or bridal party table