We’ve already seen how hay is used to say there is or there are. Now you can use va a haber to say there is or are going to be!
Va a haber mucha gente en el parque.
There are going to be a lot of people in the park.
No va a haber mucho tiempo.
There is not going to be much time.
Remember that fue and fueron can both mean went, as they are past forms of the verb ir.
But they can also mean was and were (from the verb ser)!
Ayer fue un día muy caluroso.
Yesterday was a very hot day.
Fueron unos días con mucho sol.
Those were some very sunny days.