What is the difference between моя моё мои
All those mean my, but i'm not sure the situation on when to use what.
Nearly all adjectives agree in gender & number with the noun they modify, and that includes мой which in the nominative case has 4 forms:
мой for singular masculine nouns: мой город
моя for singular feminine nouns: моя кошка
моё for singular neuter nouns: моё яйцо
мои for all plural nouns: мои города / мои кошки / мои яйца
Adjectives also agree in case: for instance, моя кошка in the accusative is мою кошку