They are in Catus soil now what other potting soil should I use??

If it were me, Christopher, I would let well enough alone - since you have so many pups something is right, Saturn. Your cactus soil looks much grittier than the types offered for sale here. As they get bigger you will be moving the babies into fresh soil anyway, but I personally would wait.

Give more light. The older leaves are flattened out, trying to maximize their sun exposure.

It's best to leave the pups until they grow some roots of their own. Then they are easier to get going once separated.

It is next to a window now getting afternoon sun maybe 1pm on

I did say you can pot them separately "as long as they have enough roots, or you can leave them for now."

Christopher