Welcome--there's certainly a wealth of clog knowledge around here!
I haven't done them on straights, but I am working on my second pair and am at the same point you are.
After you've done the 6 rows of the cuff color (in your case it would be in stockinette rather than purl all the rows, you use another needle to pick up the loops from the first row you knit for the cuff. Just slip the needle in to each loop all the way around. The cuff gets folded down and you work a three needle bind-off
to connected the stitches on your needle and the loops that you picked up.
At this point you're done with the upper part, and you make another sole. If you have any more questions, don't hesitate.