Levi'sWomen's Bermuda Shorts

I like these shorts & have a pair already in a 20 now I need them in either a 18 or 16. The lowest size to select from is a 36. What size is that?

My waist is 31 and hips 38 so what size do I order?

I don't understand the sizes 28w 29w etc. what does it mean? what would be a size 12 equivalent? thanks!

Are these plus size or juniors? I wear an 18 plus size and the 18's on these say 34 when other levi's say 38 (18 us) so I'm confused?