French language: is there much differencebetween aller, quitter and sortir? if I used the wrong one, would someone know what I meant?

Aller = go

Partir - depart from

Quitter = leave

If those differences do not mean much to you in English, then you need to look at lots of examples of "partir" and "aller" and "quitter" in French to see how those three words are used. In any attempted distinction between what seem like similar words in a foreign language, the translation of each word by one single word in English is often not helpful. In general, in ordinary conversation, you French listener would understand what you mean if you used the "wrong" word, though they might for a moment be flummoxed.

"Aller" means "to go". It's more focused on the destination, unless you add an other word like "depuis/de" (from), you don't care about the starting point.

It's the contrary of "venir" (to come).

"partir" is "to leave" in a general way, it's the contrary of "arriver". "S'en aller" is a synonym of this.

"quitter" is more definitive. If you say for example, "je quitte le Vénézuela", it implies that you will not come back in Venezuela soon.