hey everybody i just started ballroomdanceing and as a beginner I have NO idea what I need to be wearing on my feet I have looked around on the internet and I can't find any information. what should I invest in?

I know this answer isn't very helpful, but if possible you should be wearing ballroom dancing shoes. Ask your teacher for suggestions about how to get a pair. You should really have your first pair fitted in person, so don't just go buying something off the internet until you know what style and size is best for you.

Until you get a pair, you should wear leather or suede-soled shoes (no rubber or plastic or anything that grips) that fit on the snug side and are supportive. You don't want your feet to slide around in the shoes at all.

For practising, i would recommend special practice shoes. They are much more comfortable and will help your feet (because you'll be doing hours of practice each day, of course!)
If you're into comps, ask your teacher's advice, as Laura suggests. If you have the right sort of everyday shoes already, you can get the special soles and heels from specialist dance shops, and fit these. As you improve, you will have to buy specialist dance shoes

If you have a hard time finding ballroom shoes, you could also have a local shoemaker put suede (aka chrome leather) on the soles of a pair of shoes you already have.

BUT my first piece of advice would be to ask your instructor what kind of shoes he/she recommends.

A serious dancer will not wear a Latin Shoe for Modern , although some social dancers will wear Latin for Modern it is not to be recomended. Why not, why should a Latin Shoes not suite both styles. With a Court Shoe there is less to no chance of the heel getting caught in those straps. With a Latin Shoe it does happen. My own experience is my partner in the Quickstep managed to trap her own foot, this was in a competition, and we both finished on the floor.

Ladies Shoes:
Ideally you want ballroom shoes. There are several major companies that sell shoes (Supadance, Elegance, Freed, International, off the top of my head) and their prices start for competition level shoes around $90 for a real basic pair up to $150 for a real swanky pair.

Optionally, ballroom practice shoes are available, which tend to be less shiny, but really practical, they range from around $65-$100 depending on the style.

If you cannot afford ballroom shoes, then there are some other options. Basically you are looking for shoes that will not stick to the floor too much and you won't walk out of them (they fit well). (I used worn out Ked's for the first year of dancing.)

If you are doing just swing or latin, they have dance sneakers, these are ONLY good for latin and swing.

For a really cheap option you can get jazz shoes or ballet slippers. Be sure to ask for suede soled jazz shoes. These will offer little in the way of arch or ankle support, but they are better than shoes that stick to the floor (which can cause ankle or knee problems in ballroom). BUT switching to heels after dancing in slippers or jazz shoes will require more work.

Whatever you do, do not get character shoes. While they may look like ballroom shoes (and extra stable with their blocky heels) they are missing a very important characteristic necessary in ballroom heels: steel shank attached to steel plane. The amount of stress on the join between the heel and the shoe due to angle of the heel meeting the floor is tremendous (even for the light people). You do not want a shoe to snap on you. Plus asking a sales person, "Does this shoe have a steel shank in the heel?" makes you look impressive ;)

Ideally you want both latin and standard shoes, but until you are dancing quickstep or VW well enough to get your heels caught in a strap, Latin shoes should suffice. (Though technically, if you do get caught, you probably have some misalignment of your feet.) Latin shoes tend to have more flexible shoes and promote more of your body weight over your toes, whereas standard shoes are a little more stiff and balance your weight more in your heels.

I've danced in all of these from ballet slipper to real swanky. I prefer the basic competition level shoe. Absolutely positively most definitely buy your first pair of each type in person. Many dance shoes are in English or European sizes which seem easy to translate, but aren't. Also try on as many different brands as you can. They all have different characteristics (Eleangance shoes tend to be cut lower around the toes in latin sandals, Supadance tend to have narrower heels, etc. (personal observation))

Men's Shoes:
Buy ballroom shoes. Ideally two pair, one latin and one standard. If you can only afford one pair, buy whatever feels best, but not patent leather, it's really hard to dance latin in patent. They also have practice shoes that are a nice medium. Same as the ladies: dance sneakers are for latin and swing ONLY.