You need to keep repeating the 6 panel pattern rows until the sleave measures the length given for your chosen size, so the work 2 rows in patt is row 1 and row 2, these 2 don’t have increases at this time but when you get to pattern row 3 and beyond you have to work the increases at the same time as following the 6 rows of pattern.
The first one is on the next row which will be row 3 of your pattern, it says work the increase into the stocking stitch part of the pattern. 1 stitch each end of row 3, then on x following 6th or 8th own depending on your chosen size.
Then, still keeping the 6 row pattern going there is the next instruction of increases “x following 8th/10th rows”
You might find it less confusing if you circle or highlight the instruction for the size you are making.
Those 6 rows (panel patt) give instruction for the whole row of the sleeve, not just the panel, eg the “k to marker” is the stocking stitch part of the sleeve. This part will increase as you add those inc stitches in but because it always says k to m it will always be in St st and the pretty pattern will stay in line in the cente of the sleeve. Does that make sense?
I don’t think you’ve bitten off more than you can chew, I think once you get into the swing of it you will really be okay. Whilst knitting you will see that pattern progress (which you must have already done on the front, yes?) and will be able to check visually that you are in the right place.
Does it make sense?