why do we need conjugations

Question

like seriously, we don't need a new word for each person

Answer

¡Hola Carter! Conjugations are needed in order to know who carries out the action and when the action takes place. All Latin languages have different verb endings that must be learned in order to communicate effectively.
Many thanks,
Silvia.

Answer

We do the same thing in English (but to a lesser degree).  For example I go to the store but he goes to the store.

Answer

Yes you do. I go, I am going, I went, I had gone, He goes. All Indo-European languages have some form of conjugation, including even English.