You typically see that type of centered double decrease listed as s2kp or sometimes cdd. And I usually see the directions as being to slip the two stitches together. Mine never looks right when I do them separately. Comes out with a slant. I’m not sure if slipping them together will help your issue, but you might try it to keep the twist in the slipped stitches the same. Also, it’s a decrease stitch, so make sure you’re doing the slips knitwise instead of purlwise. That also makes a big difference in what you end up with.
Pictures to see the stitch steps at Twist Collective. Video at New Stitch a Day.
As to the YO, a YO isn’t a complete wrap around the need. It’s just yarn over. So for the first, you’d just bring yarn over the top of the needle from bottom to top. (If you lean to the left to look at it straight on from the tip of the needle, we’re talking going counter clockwise from 6 to about 9 or so.) Your yarn will be in the back, which is where it needs to be to do the decrease stitch.
On the second YO, you will do what feels like a complete wrap since you need to do the YO, then bring the yarn to the front for the purl stitch.