This is by far the easiest tense in the French language. It is technically only used to indicate something in the very near future or something that is about to happen. We use it exclusively, though, in the lower levels as the other future tense, le Futur Simple, is a bit more complicated and because the Futur Proche builds on previous knowledge.
This tense is created by conjugating the verb aller (this is the prior knowledge) and adding the infinitive (the non-conjugated form) of the verb you want to place in the future. Here is a reminder of what aller looks like...
ALLER - to go
Je Tu Il / Elle Nous Vous Ils / Elles
vais vas va allons allez vont
Now add an infinitive...
Je vais manger une pizza. - I will eat a pizza.
Tu vas aller au cinéma. - You will go to the cinema.
Elle va finir son projet ce soir. - She will finish her project.
Nous allons inviter les voisins. - We will invite the neighbours.
Vous allez être malade si vous mangez trop. - You will be sick tomorrow if you eat too much.
Ils vont avoir beaucoup de devoirs. - They will have lots of homework.