The Kalaam argument is essentially medieval thinking, and has a number of problems. Here's the argument in its essence:
Whatever begins to exist has a cause.
The universe began to exist (infinities do not exist, so the universe must have at some point begun to exist).
Therefore, the universe had a cause.
One problem is the notion that whatever begins to exist has a cause. Naturally, we cannot assert such to be necessarily true, because we have only the part of the universe we can observe and confirm causes to work with. So the premise is asserted on intuition. But can we apply intuition to the state of affairs before time began with the Big Bang? I think that would be risky, given how much different things were back then.
There are other problems as well, but I think most of them boil down to a lack of empirical evidence in support of the premises