The panels should equal 2.5X the width of the door

Buy a rod at least 8" wider than the frame (4" = 4"). The 4 inches on each side will give you some room to get the stacked-baked fabric off the glass. So, 144" + 8" = 152" for rod. You will install the rod 4 " wider than the window frame and 4 " higher than the frame.

The height is 98". Add 4" to it. Buy 102" length for panel.

The width of your slider is 12'. Multiply window width by 2.5 if you want curtains gathered for a full, luxurious look.

Divide your total by the width of a single curtain panel to get the number of panels you need. 144 x 2.5= 360" divided by the width of one panel.

Hang the rod first, open and install pkg of drapes one at a time, just in case you can get away with less.

For instance these panels are 102" L, 52" W, 2 to a pkg. I bet 3 pkgs could work.

https://www.amazon.com/AMPHIWELL-Blackout-Curtains-Insulated-Reduction/dp/B0995XGG9Q/ref=sr_1_9?crid=3PFKC5V8PK9MN&keywords=102%2Binch%2Bcurtains%2Bfor%2B12%27%2Bslider&qid=1653849229&sprefix=102%2Binch%2Bcurtains%2Bfor%2B12%27%2Bslider%2Caps%2C82&sr=8-9&th=1

Sorry for the long note. I was typing, doing the math, and talking to myself all at the same time.

Make a template for the 4" high, 4" wide rod install. Makes it easy.

108" tall for standard, off the shelf.... unless you are doing custom, then I'd go all the way to the ceiling and extend the road a foot beyond on each side.

You'll need a center support.

Full is always better than just enough to coverwhen closed.

JudyG Design! Wow thank you so much for all of that helpful information !!! I will definitely be following those steps!! Your time is appreciated!

Thank y’all so much!