As a student, you probably have enough reading to do... But I'd still suggest you go yourself a huge favor and buy a copy of"Understanding Exposure" by Bryan Peterson
and reading it. This is a great overview and a quick, easy read that will make it much easier to get good results. Once you've read and understand this book, I bet you could pick up and use practically any camera made with reasonable confidence and a much shortened learning curve.
exposure meters are designed to only read 18% reflectance grey, and nothing else, which is about a mid point grey. It's up to the photographer to read the scene and make adjustments accordingly.
What Jurgen replied is correct... for reflective meters, which is what all cameras have to use for their built-in metering system. Any type of meter that's reading light reflected off of the subject is going to be influenced or "fooled" by any tonalities of the subject that vary much from 18% "average" gray. Doesn't matter if you are settng the camera manually using the meter read-out, of if you have the camera set to an automatic mode... the result is the same.
Be aware that there are other types of meters, though. For example, an incidence meterinstead reads the light falling onto a subject. In this case the tonality of the subject can't influence the meter, so the meter readings are far more accurate and reliable. However, you do have to take the meter reading properly, in the same light that's falling onto the subject.
One nice thing about an incidence meter such as the one I linked to above, it can give an accurate reading of ambient light... plus it can read flash and studio strobe lighting. Many meters can't, but this type meter is designed to be able to measure the very brief "pop" of the flash or strobe.
There are lots of tools available to help determine a good exposure setting. With digital cameras we also often have to set a Custom White balance. For that, a neutral gray targetcan be used to take a sample photo and set the white balance.
It just so happens, that same target can be used to check and set up exposure settings usng the camera's built in metering system. If you fill the image area with a neutral gray target for the sample shot, then look at the histogram it will shot a narrow spike of data. If that's centered, the exposure is correct.
You also can use an 18% gray target, such as the one at the link or similar "gray cards", keeping the camera pointed at it to meter off of it while centering the indicator you were using before. That also will give you an accurate exposure.
If you set the camera to render 18% gray correctly, it will faithfully render all other tonalities as well. You still might want to tweak it a little one way or another, such as making the image slightly lighter to increase visible detail in dark areas (possibly at the cost of highlight detail).
There are also spot meters, which are reflective type too, but can be used to pick out and meter one small area within a scene. You need to learn to recognize areas of specific tonalities, then use the meter to read it to get correct settings. We used to use these shooting film, measuring not only the 18% gray, but also the darkest and lightest area of a scene, so that we could adjust the development of the film to better match the dynamic range of the scene. Can't do this with digital, though. (Instead we use mulitple shots and/or post production techniques to adjust dynamic range.)
