You need to look out for a few criteria when buying a grill. They include shape, surface area, ease of cleaning, and price. For more information, I recommend checking out our Charcoal BBQ Buying Guide.
Many people mistake putting too much charcoal on a grill, particularly when they start out. The best way to determine the charcoal you need is to think about the temperatures you are targeting. The more charcoal you use, the higher temperatures you will get, while the lesser charcoal you use, the lower temperatures you will achieve.