Trouble understanding a pattern

#1

I’m coming back to knitting after a long absence this is my first attempt. Can anyone help me please?

I’m having trouble with a couple of instructions in my pattern. Here goes:
The pattern reads: Cast off 4 sts beg of next 2 rows 63 sts.
1st Row. K1, s1, k1, psso, yfwd, s1, k1, psso, Knit to last 5 sts, k2tog, yfwd, k2tog, k1, 61 sts
2nd row. purl
1st and second row set eyelet holes and raglan shapings. Keeping continuity of eyelet holes as set (throughout) work 24 rows dec 1 st as before at each end of next and every foll alt row. 25 sts

Question 1 has to do with the casting off of the first 4 stiches so I do this at eash of the 24 rows ( since this constitutes the pattern) or just the the first 2 rows?
Question 2 Do I work 24 rows including the first 2 rows or 24 rows after the 1st and second rows?
Question 3 I’m not sure about the decreasing 1 st as before at each end of next and every alt row. Is this in addition to the above instruction?

Help I think I bit off more than I can chew !!!

#2

Casting off–only cast off at the beginning of the next 2 rows–that will be your underarm shaping (I’m assuming that this is a sweater)–you’ll have 63 stitches left on your needle.

The raglan shaping comes from the decreases that you’re doing toward the ends of each row.

You’ll do row one with the decreases as written–this is the right side.
Purl across on the wrong side.

Rather than worrying about counting rows, just decrease at the end of every right side row (which are the alternate rows) until you have 25 stitches left on your needle.