The pattern is worked in waves by increasing and decreasing stitches across every few rows. It is not a hard pattern to do with two design repeats, one on top of the other. After several rows you should be able to make it without looking at the pattern.
It comes in 3 sizes from a small 26” x 32” to a large 46” to 60”. That is the reason for such a wide division in yardage amount. It is shown in 2 styles. One with the same color throughout and one with stripes. Alternating the Main Color (MC) and a Contrasting Color (CC). It can be done with 2 colors or alternating with 3, 4 or 5 colors. your choice makes it unique to you.
I wouldn’t worry about the gauge much. Afghans are very forgiving. No matter what size they end up, whether a small being a litter bigger or the large one a littler smaller. They are all warm and cozy.
I used a 32” circular needle for the smaller size and a 36” circular needle for the 2 larger sizes. Nothing else needed to make afghan, just yarn and needles.
The smaller afghan needs 2 to 3 balls depending on the put up in yardage and the largest one requires between 7 and 8 balls depending on the put up, unless you are using Red Heart Super Saver which is a very large ball, then only 1 or 2 would be needed.
If you are changing colors, then 1 additional ball of each additional color would be needed which would also reduce the amount of the main color.
I use a loose bind off to finish my afghans. Its really easy to make the bind off tight with the usual method. I have a YouTube Video that shows 3 different bind offs called “Bind Off Regular, Loose and Very Loose by Stitch Niche. I carry the Carlton Loyal Aran in my shop.