This quilt is done on point which means that your rows are put together differently. You won't be sewing horizontal rows like most quilts. The best piece of advice for me to give you is lay it all out. That way you'll have a visual. The short sashing between the block are sewen block to block. Then you would cut and piece the longer sashing for between the rows.
When you do sew your rows together you're going to be sewing rows that are on an angle.
Does that make sense, if not PM me.