What a cute outfit. Ecru and white are so crisp together. Wearing the sweater off the shoulder, a denim skirt with a frayed hem, and some well-worn Converses makes it feel really casual and fun. No accessories necessary.
This is a drop shoulder pullover with no waist shaping and minimal neck shaping, 4-6 inches of positive ease. We'll call it boat neck shaping because it's so huge, it really doesn't matter. Knit the front and back rectangles flat and separately with 1-2 inches of 1x1 ribbing on the bottom edges. You can put in a little neck shaping if you like but I would just be lazy and leave all of the edges straight. Seam the body pieces, leaving a very wide neck hole that is 75-90% of the shoulder width, and the sleeve holes and the bottom 1/3 of the side edges un-seamed.
Knit the sleeves flat or in the round and joined to the body. You can't see it in the picture, but I would also put 2-4 inches of 1x1 ribbing at the wrist. It leaves the option of having one or both sleeves unrolled.
I could see using a 100% cotton like Sugar n' Cream or Peaches & Cream. It's a pretty large sweater, so less expensive yarn will give you a rustic look after a couple of washings and save you some cash. Blue Sky Alpacas has Organic Cotton in great colors and Knit Picks Simply Cotton Organic Worsted comes in natural un-dyed colors. Knit Picks' Shine Worsted is a cotton/rayon blend, which will add some more durability and a little shine.
A bamboo yarn like Bam Boo by Classic Elite Yarns would be gorgeous and shiny and heavy and a little more expensive. I've used Bam Boo and I like it. I would really go with the washing instructions. Machine washing will be fine, but it gets really roughed up and looses a lot of the gorgeous sheen.