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)
+ infinitif
Je
vais
manger
voyager
boire
lire
écrire
Tu
vas
Il
va
Elle
va
Nous
allons
Vous
allez
Ils
vont
Examples
Je vais le faire. = I will do it.
Tu vas la connaître. = You will meet her.
Nous
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
una cosa.
Italian: Vada
a dirti cualque cosa.
French:
Je
vais te dire quelque chose.