Personal notes to clarify confusing writing of an easy pattern. My edits in bold:

DRESS
First rows: CO and k 4 garter st rows. Ignore extra 4 k rows in pdf.
…

• Underarm round (RS): Cast off for arm holes like this: K 4 (5) 7 (9) stitches past the first SM, cast off 6 (6) 8 (8) stitches. Repeat on the other side. K to end of round. K 9 (13) 13 (17) stitches past the last SM. You are now in the middle back, and will start knitting back and forth.
• Sleeve round (RS): Use the pattern colour (green). Knit 1 row, but when your reach the arm holes, cast on 18 (26) 32 (38) stitches on both sides, (make backward loops). When you reach the end of the round, turn to begin to work flat.
• Sleeve row (WS): Knit one row.

HAT
CO with pattern color (green) and k 2 rows flat.
Position woven stitch bands so each bump alternates over the odd number of stitches like a checkerboard (don’t align them vertically).

BOOTIES
In preparing you for what’s next, pattern seems to duplicate instructions. The formatting of special instructions for other sizes makes it even more difficult to interpret. So, here’s the gist:

• Cast on using the pattern main colour.
• Knit 2 rows back and forth.
• Knit woven stitch, checkering woven color bumps across the odd st number for correct number of repeats.
• With pattern color, k to last 2 sts, k2tog.
• Switch to main color, purl 1 row.
• Knit a row with holes for the cord: K1, YO, K2tog 4x total, K 4 sts, YO, K2tog, K1 4x total.
• K 10 (Knit this and last sections of the row in garter stitch), PM, P 8 (knit this section of the row in stockinette), PM, K 10.
• Increase row: kfb one stitch before the first marker and one stitch after the second marker.
• Knit increase rows until you have 50 sts in row.
• Knit entire row in garter stitch from now on: K 4 rows, and on the last row PM’s before and after the middle 4 sts.
• Knit 1 row.
• K to 2 sts before M, K2tog, k to second M, k2tog, k to end.
• Repeat prev 2 rows 3x total. Bind off and assemble.

Comments:
Giving the newborn size a try. It should be quick enough that if it’s super tiny, I’ll just save it as a hand-me-down and make another for baby to wear next. Achieved gauge with US 5 needle and Knit Picks Palette fingering yarn held double. Size seems to be good for newborn!