Welcome to the world of knitting, and to this forum. Knitting is a great hobby. Just ask anyone here.
Everybody has favorites about needles and sizes. I like to start people off with a needle big enough to help the work go fairly fast, but not the super big needles that can be awkward to manipulate. I think something in the range of an 8 or 9 is nice.
The most common needles you'll find in non-yarn shops are likely to be aluminum and often the 14 inch long ones. I don't like those at all. I never use a 14 inch long needle, they are, in my opinion unwieldy to use. But some people love them.
I suggest you look for needles 10 inches long and if you can find them, some more non slippery material is nice. Bamboo or wood can be found sometimes, even plastic-like. I have a lot of older circular needles that are nylon and I love them. You could use a circular needle right from the beginning, but it confuses some people at first. If you go that route, just treat each end of the circular as you would if it were a regular straight needle and use it to knit back and forth in a flat piece of work. If you get a circular needle, don't begin with a real short one. 16" are common and there are some even shorter. These are a blessing for their purpose, but not the easiest to start on. Most anything longer--24in, and up would be better.
Any needle you are able to come up with will work to begin with, but if you have choices those are my ideas. A medium weight yarn in a lighter color and without anything weird going on, like nubs or eyelashes, is the easiest to begin with. By light color, just don't get real dark, black is bad to start out with, but a bright color like red would work. Get a color you like.
As far as a pattern goes. Some people like to jump right into a project, but be aware that as you learn your knitting will improve and often these changes can make a first project uneven. I kind of like people just to experiment at first and not really make anything, or make something like a very simple scarf, maybe even that you would be willing to make as a sort of sampler of things you learn. Then after you learn the basics you can pick most any project that you think you are up to trying. A lot of us like learning one or two new things on a project and just letting our skills build over time. Read through a pattern that interests you and if you know how to do most
of the things given and just looking at it doesn't make you freak out, you can probably do it.
The forum folks can usually help you out if you need it.
Also you will want to check out the free videos on this site. They are very good for helping you learn to knit. Have fun.