Salut! Comment ça va?

French doesn’t have a specific verb tense to say sentences like these:

What are you doing? –> I’m doing my homework.

What’s he doing? –> He’s cleaning his car.

We have two ways of saying this. The first one is to use the present tense:

Qu’est-ce que tu fais?
Je fais mes devoirs.

Qu’est-ce qu’il fait?
Il nettoie sa voiture.

Now when you also have the verb expression être en train de, which means to be in process of doing something. You use it when you want to insist on the ongoing nature of an activity. Here are some examples:

Je suis en train d‘étudier pour mon examen. [I’m studying for my test.]
Tu es en train de faire tes devoirs. [You are doing your homework.]
Il est en train de nettoyer sa voiture. [He is cleaning his car.]
Elle est en train de se maquiller. [She’s putting makeup on.]
On est en train d‘attendre le bus. [We are waiting for the bus.]
Nous sommes en train de jouer au football. [We are playing football.]
Vous êtes en train de parler français. [You are speaking French.]
Ils sont en train de se préparer pour l’entrevue. [They are preparing for the interview.]

If you don’t want to emphasize the time nature of the activity and only express the activity itself you could say:

J’étudie pour mon examen. [I’m studying for my test.]
Tu fais tes devoirs. [You are doing your homework.]
Il nettoie sa voiture. [He is cleaning his car.]
Elle se maquille. [She’s putting makeup on.]
On attend le bus. [We are waiting for the bus.]
Nous jouons au football. [We are playing football.]
Vous parlez français. [You are speaking French.]
Ils se préparent l’entrevue. [They are preparing for the interview.]

C’est tout pour aujourd’hui! On se voit!