Hay    there is / there are

Hay mucho en México

Are there places you go to a lot?
Is there an activity you really like?

To say, yes, there are, or yes, there is, you'll need the word hay
You're going to love the word hay. It is the easiest verb to use.

hay = there is, there are

     ¿Hay una pizza en la mesa?
     Is there a pizza on the table?
     Hay una pizza en la mesa.
     There's a pizza on the table.

     ¿Hay tres pizzas en la mesa?
     Are there three pizzas on the table?
     Hay tres pizzas en la mesa.
     There are three pizzas on the table.

Notice that the above sentences in English started in four different ways, but in Spanish, all you needed was hay