The passé composé can be translated with the present perfect or the simple past in English. We use it to indicate that an action in the past has been completed. We use this form in particular to emphasise the results or consequences of the action.
The passé composé is often used instead of the passé simple in everyday language. it is a single complete action in the past.
In order to construct it, we need the present tense forms of avoid/être and the past participle (participe passé)
AvoirJ'ai Tu as il/elle/on a Nous avons Vous avez ils/elles ont
Etre je suis tu es il/elle/on est nous sommes vous êtes ils/elles sont
For regular verbs, er/ir/re verbs, the past participle is easy to construct:
ER = é eg. aimer = aimé
IR = I eg. finir = fini
RE = U eg. vendre = vendu
However there are a lot of irregular verbs and faire is amongst them.
FAIRE = Fait
AllER = allé
So now, the verb faire and its past participle fait takes the auxiliary verb avoir and becomes:
Faire J'ai fait Tu as fait Il/elle/on fait Nous avons fait vous avez fait ils/elles ont fait
In contrast, aller is one of the 14 verbs of motion and staying still and takes the auxiliary verb être. The easiest way to remember these verbs is DR MRS Vandertramp Mnemonic
Devenir Revenir
Monter Retourner Sortir
Venir Aller Naître Descendre Entrer Rentrer Tomber ResterArriver Mourir Partir
Aller Je suis allé Tu es allé Il/elle est allé Nous sommes alléVous êtes allé Ils/elles sont allé
Here are the conjugations of these verbs. If you have any questions about anything I've said, I'm happy to clarify anything and explain it in more detail. It is difficult to understand at first but with time and practice, it'll become easy.