There is a simple alternative for the futur simple, which is also used quite more often in everyday life than the futur simple: the futur proche . It is a composed of the conjugated form of the verb aller (to go) and the infinitive. One could say it is the French version of the be-going-to-future.
Das futur composé
aller (to go)
Je vais le faire. = I will do it.
Tu vas la connaître. = You will meet her.
allonsêtre heureux. =
We will be happy.
Both, the futur simple and the futur composé describe actions in the future.
For people with knowledge of other Roman languages - here is a difference between Spanish and Italian on the one side and French on the other. French does not use a preposition:
Spanish: Voy a decirte
a dirti cualque cosa.
vais te dire quelque chose.