The futur simple corresponds to English "will" and is formed by adding a single set of endings — -ai, -as, -a, -ons, -ez, -ont (which look like the present tense of avoir) — directly onto the infinitive: parler → je parlerai, tu parleras, il parlera, nous parlerons, vous parlerez, ils parleront.
For -re verbs, the final e is dropped before adding the endings: vendre → je vendrai, not je vendreai. This tense is more common in writing and formal speech than the futur proche, and it's the standard tense for predictions, promises, and the result clause of a si-clause (si tu viens, je serai content — if you come, I will be happy).