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In Judaics class at school:

Teacher: In Judaism, there are a lot of variations on how to follow customs. There's Askenazim and Sephardim, and within that there are always variations from community to community. In such matters as choosing which particular customs to follow, you always do the customs which your Jewish Dad does.
Me: My dad's not Jewish.
Teacher: Then go by your Shul's Rabbi.
Me: I am a Jew with no Rabbi; I'm in between shuls.
Teacher: The you get the best of all worlds.

So... I know I'm going Ashkenazic because my mom and her side of the family is Ashkenazi. But there's still so much more to decide, we jews haviong to debate all the infinatescimal details of this or that!

What exactly do I do, then?

No, I get what he meant, it's just that something you're going to learn about Jews is...
We've been around for 5,000 years and the only thing we totally believe is straight from G-d is the Torah, which really doesn't say much.
The Talmud, the Midrashim... Rabbis have been arguing for thousands of years about which cup of wine to drink first, how to pronounce this word and that one, how many prayers to say and when to say them, what to wear, how to practice your Judaism.
Again, EVERY INFINATESCIMAL DETAIL. And I don't have a Jewish Dad or a Rabbi to tell me at what pitch and with what intonation to say this prayer and what general attitude I should have towards this cutom...
I have to pick and choose for myself out of literally HUNDREDS of ways to drink wine, light candles, say prayers, interpret Torah, Read Mishne, Cite Gemarrah... really, to do anything and everything.
How the hell do I do that?

That doesn't work in Judasim. Everything's a choice, you can't just act. There is double signifigance in choosing. Making these Choices defines who you are as a Jew, what kind of Jew you are and are going to be. You can't just do whatever and wave it off.

I don't know exactly what kind of Jew I want to be. If I don't decide, I'll be a BAD Jew.
A choice made thoughtlessly is infinitely less significant.
Feel free to disagree with me, but we won't get anywhere that way. We clearly have some huge fundamental differences.
Anyone else?

Yes.

Now does anyone else have an answer?

Your first assumption of hundreds of methods behind all methods is actually way off base.

I am going with the assumption you are looking to be a practicing jew as I understand to be religious but having no qualms with TV, internet etc. All while keeping the sabbath,holidays, kosher etc.

There are actually 5 major groups each with only a few subgroups if any.

1. Ashkenaz- (yay! I'm one) We generally hold approx 5-6 hours after meat for milk, although there is a tiny sect that hold 1 hour (you can chose this but if you are among jews it will seem odd.) You can buy an ashkenaz siddur anywhere that sells sidurim and be fine in all your prayers.

2. Sefardim - like ashkenaz in many respects but usually have a different pronunciation more akin to Israeli's. Again, you can buy a Sephard siddur anywhere. They never wait 1 hour however 3 hours isn't uncommon.

3. Sefaradim - usually meroccan, israeli or middle eastern dissent have special "Sefarady" davening with a few special customs (ex. tallis at 13). Usually only hold 3 hours.

4. Chassidim - they Daven Sefard but there are many many subgroups with special laws. Usually people convert to a specific Chassidic rabbi after meeting a Rebba who profoundly changes there life in a short time.

5. Libavitch - They are relatively well known, they Daven what is called "Nusach Ari" they wear two sets of Tfillin instead of one.

Most of the Halachos of Ashkenazim and Sephardim are clearly discussed in the Shulchan Orech and Halachah is usually dictated directly from the Shulchan Orech.

I may have gotten some stuff wrong but it seems to me like you should ask your mom exactly what she was and if she has any living practicing relatives you can learn from.

P.S. chassidim are technically sefardim.

I've already established I have no idea how to spell whee

Sorry I have several Sefard and Sefaradi friends who would argue vehemently with you. Furthermore Chassidim never daven Nusach Ari or wear the second set of teffilin the way chassidim do. I had a clase Lebavitch friend growing up and my wife's extended family is chassidic. The only strong similarity is they both have (ok one had one has) a Rebba.

P.S. Most of the minutia aren't that important. Getting the basics is better and prayer is uniform (I recommend Artscroll, though it can be expensive they are amazing and include all the prayer laws, in the back as well as easy to follow instructions about the prayers)

Again, there aren't nearly as many variations as you assume.