Voici est mon pere, Mark.
Voici, mon pere, Mark.
OR, Mon pere Mark est ici.

Here is a list of some of them in the order [Masculine Singular], [Feminine Singular], [Plural]:-

***My: [Mon], [Ma], [Mes]***
Your(singular): [Ton], [Ta], [Tes]
His/Her: [Son], [Sa], [Ses]
Our: [Notre], [Notre], [Nos]
Your (plural): [Votre], [Votre], [Vos]
Their: [Leur], [Leur], [Leurs]

Examples:-

Their books – Leurs livres
His/Her brother – Son frère
Our bedroom – Notre chambre
Your(singular) friends – Tes amis

Probably a bit too in-depth, but there you go. Good luck!

My: Mon=masculin, Ma=Feminin, Mes=Plural m/f

In your sentence I used "mon" because the noun "pere" is a masculin word.

Are the forms of the French ‘my.’ It’s the same with ‘your’ (ton, ta, tes.) Translation for your sentence, Voila est mon pere, Mark. The translation the form of My is according to the subject you are referring to. Bon Chance avec le langue!

It goes by the word, masculine, feminine or plural (masculine and feminine plural are the same), not by the person saying it.

The only exception is if it’s a feminine word that starts with a vowel, in which case you say "mon" and pronounce the "n".

Mon amie (my female friend)