Music stands are really really useful if you're going to be playing from sheet music. If you're trying to play from sheet music without a music stand, you'll most likely probably damage your posture, by trying to bend over to see the sheet. So it's important to make sure that the sheet music is displayed in front of you at exactly the right angle.
So-called 'wire' music stands are the most portable and inexpensive, and therefore usually the most common types you'll find. They're used by violinists around the world. There are other types of music stand; heavier stands will generally be used in venues where they won't need to be moved too much. Portability (especially weight) should definitely be taken into account when choosing a music stand!
If you anticipate having to travel regularly with your music stand, even if that's just to your weekly orchestra rehearsal, you might want to consider a music stand that's designed for travelling. Although they are actually full size, these music stands are extremely light weight and easy to carry.
Exercise: See if you can set up a wire music stand in under 30 seconds!
If you're using a wire stand, remember the mantra 'Big Ears Up, Little Ears Down'. It's a great way of remembering which parts of the metal structure should be pulled in which direction, when unfolding the top half of the stand.