Unfortunately, any of the Nikon lenses to fit your needs will be beyond your budget.
For portraits, you want a lens that is a moderate telephoto, around 85mm to 100mm. However, some pros have taken to using a 70-200mm zoom. While there are a lot of personal preferences in this regard, a good portrait lens must have two characteristics:
Focal length. As I stated, anywhere from 85mm and up. You do not want to use a wide angle lens for a portrait lens as wide angle lenses distort facial features; fatter face, big nose, etc. Of course, you can use a wide angle zoom lens if you put the zoom to the telephoto end.
Fast lens. A faster lens provides more limited depth-of-field, which results in a background that is blurred. The best portraits have a blurred background so that you are not distracted by it, and your eye is drawn to your subject. The faster lens the better in this regard.
For macro use, you will find many lenses that claim to have macro capability. But these are not true macro lenses. A macro lens is one that will focus 1:1, and most of the lenses that claim to have macro capability cannot achieve 1:1. The term 1:1 is a ratio, meaning the subject is life-size. In other words, with a 1:1 ratio, a 1/2" bug in real life would occupy a space of 1/2" on the sensor.
True Macro lenses are also available anywhere from 35mm to 200mm. I would try to get one that is 100mm or longer. If you use a shorter focal length macro lens, the lens might be so close to your subject that you will scare it away. Longer macros will allow you to stay back a bit. While shorter length macros are less expensive, they are generally limited to flowers and inanimate objects.
The good news though, is most macro lenses are fairly fast, and for those that are 80mm to 105mm are also good portrait lenses. For instance, the Nikon micro 105mm lens is a fast f/2.8. Another great macro lens is the Tokina 100mm f/2.8, which is the lens I have. Unfortunately, the Tokina does not have an internal focus motor, so for Nikon cameras, it won't auto focus on D5000/D5100/D3000.D3100/D40 or any other Nikon DSLR that does not have a built-in focus motor.
But... when you are shooting macro you usually manually focus anyway, so the Tokina lens is not an issue in that regard. However, if you want to use it for portraiture as well, then autofocus might be something you would desire.
Nikon does make a 105mm macro that will autofocus on those mentioned Nikon bodies, the AF-S version, but it costs $1k, which is double of what the Tokina costs. I'd rather put that money into a Nikon D7000 and buy the Tokina, which can autofocus on the D7000.
For landscapes, most "kit" zoom lenses start out at 18mm, which is decent for landscapes. However, you can go one step better with a super-wide angle lens. Nikon and the 3rd party lens makers all make them, and they can offer a 50% wider shot.
I have a Tokina 11-16mm, and it is probably better than Nikon's 10-24mm, at lest in the DX format. But again, in the case of Nikon, the Tokina lens does not have an internal focus motor, so it requires a Nikon body that does (D90/D7000 and above).
Nikon's 10-24mm lens does have an internal motor, so it will focus on the less expensive Nikon cameras, but again, it is 25% more expensive than the Tokina.
I am including a link to Nikon's lens simulator. It lets you see the difference in a 10mm and 18mm focal length for landscape use. Once you see the difference, you'll likely agree that the super wide angles are highly desirable for landscape use.
One last comment. You mentioned you were confused by all of the different Nikon lenses available. They can all be summed up as follows:
Autofocus capability: Lenses will either have an internal focus motor, designated AF-S, or require the camera to have an autofocus motor, designated as simply AF or AF-D. Nikon's entry level cameras (anything less expensive than a D90) do not have internal motors, and you must use AF-S lenses to autofocus with them.
Professional vs. Consumer grade. All of Nikon's professional grade lenses will be f/2.8 or faster, and most of the zoom lenses will be constant aperture. Another easy way to tell if the lens is professional grade is the price. If it is more than $1k, it's likely a professional lens. Consumer grade lenses on the other hand are usually slower (f/3.5, f/4. f/5.6, etc). These are less expensive, but don't have the low light capability or the ability to blur backgrounds (in the case of a portrait lens) as well as the pro lenses.
Since you are in high school, join the camera club if there is one, or at the very least, take a camera class. If your high school doesn't offer a camera class, your local community college most certainly does, and if you are a high school senior, you can probably take the college class this year.
Hope this helps.