How do you find the point estimate?
In AP Stats, the point estimate is the observed sample mean or sample proportion. For a two-sample interval, it is the difference in the observed means or observed proportions.
it is the center of the confidence interval
will it be given or do we have to calculate it?
if 0 is included in the interval what does that mean again?
That is it plausible that there is no difference
Depends. As Krish said, in a given interval, we assume in AP Stats that the point estimate is in the center. Use the midpoint formula: (left endpoint + right endpoint) / 2.
When constructing your own, use the sample statistic or difference as the center.