Joachim's answer provides very good info focused on the archival aspect to what makes a "good paper" in your question.
But he just touches upon the two most critical aspects of what makes a good paper as far as drawing on it is concerned: the weight and the tooth of the paper. Weight being a combination of thickness and durability, tooth being the amount of texture and/or roughness of the paper's surface.
When drawing in charcoal (or pastels, or pencil for that matter) the texture of the surface plays a huge part in the final work. A light broad stroke of the stylus brings out the texture which can add great dynamic to your shaded tones. Tooth also serves to grab the charcoal so that the drawing is easier to put down and also less likely to smear away.
The weight of the paper provides resistance to wearing away or tearing. The heavier the paper the more vigorous you can be when working, giving you more range and flexibility in your style. Dry media can build up quickly, heavier paper allows you to put down more pigment before the paper becomes overloaded. Weight of the paper is shown in pounds (per 500 uncut sheets -- 17" x 22" for regular paper, 20" x 26" for cover stock) and ~65lbs. would probably be the minimum you would want to go for charcoal/pastel work. If you were to be working on >150lbs. paper you could start to do things like scratch away pigmented areas without destroying the paper.
At this point in your drawing career experimentation is critical. So focus less on permanence and more on expression. Find things to draw on that are not what you would consider paper at all: Canvas, bark, shopping bags, cardboard. Different textures can result in a very different look to the drawings. The idea is to do a lot of different works without worrying about anything beyond the moment of their creation.
Then take that experience with you when picking out the nicer drawing papers at the art store. Even then keep experimenting, like with Japanese washi papers, watercolor paper, etc... But then you will know what you are looking for in the paper. As far as keeping it going on a budget many times there is a bin of slightly damaged papers, a good way to try out the more expensive ones.