Hi Dodyan. If you find that part too confusing, it's perfectly acceptable, and common practice, to pick up just one stitch in the middle of that crux of the thumb area, wherever you like. You will have a gap on either side, which can be later closed up with the end yarn using a yarn needle, as I also demonstrate in the video. Picking up three stitches over the gap, and decreasing two of them on the next round, is an option that I demonstrate in the video, but hardly a requirement.
And yes, I believe I begin the picking up stitches with the fourth needle, which then knits the stitches off the following needle, freeing up the fourth needle once again, which is necessary to continue working.
I'm glad you're enjoying the pattern. Good luck with that part, I hope this is clear enough for you.
KnittingHelp Queen Bee
"There is a vitality, a life force, an energy, a quickening that is translated through you into action, and because there is only one of you in all of time, this expression is unique. And if you block it, it will never exist through any other medium and it will be lost. The world will not have it. It is not your business to determine how good it is nor how valuable nor how it compares with other expressions. It is your business to keep it yours clearly and directly, to keep the channel open. You do not even have to believe in yourself or your work. You have to keep yourself open and aware to the urges that motivate you. Keep the channel open."
— Martha Graham