can someone help dumbdown this pattern?

this is a pattern I am looking to knit. I am a beginner. Ravelry says its a beginner patern.

so the first its sayin gto make the gauge…why is the gauge so big? its a lot of yarn I feel for somehting that isnt apart of your project. it tells you how many stitches and then it says to do garter sts : knit all sts…why is it saying knit all sts but it first said garter sts? and does this apply to all the prject or just the gauge?

then it says seed sts. but it hasnt told me yet how many sts to cast on. is it just saying it generally for the whole project?

then it goes to button holes, so my understanding is hat its not telling me to go do the buttonholes now, its not in order on how to do things?

then it finally gets to the jacket, knit back and forth on the circular needs, it means knit one side then purl the next?

then it says cast on new sts each side for sleeves on every other row, does it mean add the st at the very very end or between the last st and second last stitch?

is this really a simple beginner cardigan?

Drops patterns, like many patterns, starts by defining the sts and techniques required later in the actual pattern. Garter stitch is the pattern that you get in the knit fabric when you knit every row. This pattern and the gauge swatch are knit in garter stitch.
In order to make sure you’re using the correct yarn and needle size for the size sweater that you want, you need to knit a gauge swatch of about 5 inches square. This is so you can measure the number of sts over the middle 4 inches. So cast on about 30 sts for the swatch. You can save the swatch or rip it out and use the yarn for the sweater. Here’s a good explanation of gauge.

Once you get to the jacket pattern itself, the pattern recommends a circular needle but it wants you to knit in rows (i.e. back and forth) and not to join to knit in the round. You’ll still be knitting every row.

The cast on sts are at the very edge of the body of the jacket. These will form the sleeves. Use a knit or cable cast on for this addition of sts. (Videos for these are under Free Videos at the top of the page, Cast Ons)

Although Drops patterns are sometimes challenging translations, this is a fairly straightforward pattern. It’s a reasonable start at working patterns.