Can someone please explain to me the word "en", like why you would use it and it's different meanings? It seems like there's 50 ways to use it and I'm lost!

Ahá! You must have just "met" "y" and "en?" I'll just explain "en" as that's what you asked for.

1. en = indefinite pronoun & adverb.
The pronoun "en" replaces "de + noun" and generally refers to things. It is usually translated into English by "some, any, of it (them), from there."
"En" is always expressed in French, even though the equivalent may not be expressed in English. "En" must be used when the noun is omitted after a number, an adverb, or noun of quantity, or an idiom requiring "de."

EXAMPLES:
Voici des framboises. En voulez-vous?
Here are some raspberries. Do you want some/any?

Elle n'en a pas acheté.
She didn't buy any. (She bought none.)

N'en parlons plus.
Let's not speak of it any more.

Vient-il de la ville? Oui, il en vient.
Does he come from the city? Yes, he does (come from there).

Je cherche un taxi. En voilà un.
I'm looking for a taxi. There's one.

Avez-vous de la monnaie? Oui, j'en ai assez.
Have you any change? Yes, I have enough (of it).

Qui se sert de cette plume? Moi, je m'en sers.
Who is using this pen? I am. (using it)

NOTE: 1. Like personal pronoun objects, "en" egularly precedes the verb, except in the affirmative imperative, when it follows.
N'en avez-vous pas? Prenez-en.
Don't you have any? Take some.
2. There is no agreement of the past participle with a preceding "en."
A-t-elle reçu des lettres? Non, elle n'en a pas reçu.
Has she received any letters? No, she hasn't. (received any)

2. en = preposition, meaning "in; into, to, at, at, on, by, (made) of, even as" as in "to go to France" = aller en France / from bad to worse = de mal en pis / at sea = en mer / at war = en guerre / on leave = en congé / by rail = en chemin de fer / (made) of wood = en bois / he died as a soldier = il est mort en soldat

3. en = in idioms!
en (when one is inside the means of transportation), by = en automobile (auto) / en avion / en bateau / en chemin de fer / en voiture
en arrière = backward(s), behind
en bas = downstairs
en haut = upstairs
en effet = (yes) indeed, as a matter of fact
en face de = opposite
en famille = as a family, within (in the privacy of) the family
en même temps = at the same time
en plein air = in the open air, outdoors
en = late (not on time)
en tout cas = in any case, at any rate
en ville = downtown, in (to, into) town

Hopefully, that will about cover the subject of "en" but feel free to ask any other question(s) you may have.

Sra (aka Mme)