Went into work, clocked in. Was told by my boss to wait around. Then they told me that I was being laid off immediately. My question is, shouldn't I be paid at least 4 hours for coming in that day as scheduled???

There is no "reporting time" pay requirement in Virginia.

Since you were instructed to "wait around" that time is compensable, but only to the extent you were actually there. What you were scheduled to work is legally irrelevant.