Need help adjusting sock pattern

I am almost finished with my very first pair of magic loop socks!
As I am knitting the second sock, I am convinced that I want to learn to do two at once!!! I also did this pair cuff down. I want to try toe up next time.

So I am looking at this pattern to make socks for my son:

He is almost 4 years old and wears a child size 9 shoe. I want to make them a little big so he does not outgrow them too quickly.

I am also open to using another pattern along as it is is toe up, magic loop. I was hoping to do something different than the basic ribbing on the cuff this time as well…

Thank you SO MUCH for the help

I have NO idea how to adjust a sock pattern on my own…

I love Silver’s sock tutorials and also would be thrilled to love her toe up on one circ if I could figure out the math…

I am using fingering weight yarn and I knit so losely I am using a size 0 circ.

I have had some success using the Knitting Fiend’s Sockulator
to create a basic pattern. You will have to adjust for the pattern.

I looked and saw that you need to use a dpn at some point with this pattern?

Could you take the numbers it gives you and input into silver’s tutorial?

The needles you use should have no impact on the finished product (as long as the gauge is the same). I start with two circular needles for the toe, move to a single 9 inch needle for the base of the foot, two circulars to turn the heel, and then to magic loop if I am doing a knee sock (kilt hose). At any point I could use DPs.