If you are really new to knitting, you should start getting needles with the projects you tackle. If you get a different type a few times, you will know if you like them.
We all have our favorites. I mostly love metal needles (partially they are hollow ones to save weight), but I do have wooden ones and bamboo that are great, too. I do not fancy plastic / acrylic needles. My personal taste.
I love circular needles. I do not own straight needles (those that come to an end) other than the ones I inherited from my grandmother lately. I do have double pointed needles, though.
The uses: You can do pretty much anything you can do with straight needles (I have not really seen any purose that will not work out.)
In addition IF the diameter is right you can knit tubluar things like cowls, hats and so on on circulars. But the diametre has to fit. There are lots of different ones, and lots of projects so that is a funny puzzle.
You can use rather long circulars for magic loop or single loop ( other techniques for working in the round when the diametre does not fit)
Double pointed needles are used to work in the round (like socks, hats and such) and you use sets of 4 or 5 (customary to certain regions) to form the circle with all but one of them and use the remaining one as working needle.
You can tell, I love my circs :o)
Other knitters will tell you other stuff. Everybody has their opinion.
I have a big arsenal of needles, also because I often work on several projects at once and keep them kicking around on the needles.
I did find my perfect "one for all" with the Knit Picks set of circulars with removeable cables (needle tips and cables seperate). They are also sold under "knit pro" - there is at least one other maker of these kits and that is Addi.
(and there are the "Rainbow Denise" that are advertised on kh.com
- another adjustable system)
The Knit Pick / Knit Pro come in rosewood, composite wood, acrylic and metal (which I have). and you can get a basic set (price in the US? no clue) and enlarge it as you need.
But that does not say that I do not use any other needles any more. I keep buying needles every once in a while, too. So: A happy selection of different things is a good thing. Start your collection.