hrhofmann wrote:

We had some very delicious cherry tomatoes from our local supermarket.
If we plant the seeds from those tomatoes, what are the chances of actually
getting some of the seeds to sprout, or are the seeds likely to be infertile
because the tomatoes are some sort of hybrid?

Hybrids will produce but rarely true to form.

Do I have to dry them for some period of time before planting??

Only if you intend to save them, if planted immediately drying is not
necessary.