Simple Past (Passé Simple)
* j'eus (I had)
* tu eus (you had)
* il/elle/on eut (he/she/one had)
* nous eûmes (we had)
* vous eûtes (you had)
* ils/elles eurent (they had)
Past Participle (Participe Passé)
* eu (had)
Compound Past (Passé Composé)
* j'ai eu (I have had)
* tu as eu (you have had)
* il/elle/on a eu (he/she/one has had)
* nous avons eu (we have had)
* vous avez eu (you have had)
* ils/elles ont eu (they have had)
Imperfect Past (Imparfait)
* j'avais (I had)
* tu avais (you had)
* il/elle/on avait (he/she/one had)
* nous avions (we had)
* vous aviez (you had)
* ils/elles avaient (they had)
The most common past tense for "avoir" is the compound past (Passé Composé), which uses the present tense of "avoir" and the past participle "eu".
It's important to understand the different tenses of "avoir" to correctly conjugate verbs and understand the nuances of time in French.