I think you need to decide which sort of cichlid you're going to go for. There are three main 'families';
South American: tend to be smaller and more peaceful. Many can be kept in planted tanks and in communities. Most prefer softer, acidic waters, often tannin stained.
Central American: vary from large to very large, and from semi aggressive to very aggressive. Robust planting, if any, and tough tank mates. Most prefer medium to hard waters, neutral or slightly alkaline.
African: mostly very aggressive, and most for species/cichlid only tanks (many people concentrate on keeping fish from one river or lake; Malawi, or Victoria, for example). In general, African tanks need to be kept very heavily stocked to keep the aggression spread around. Need very hard water, heavy filtration and water changes, because of the heavy stocking, plus lots and lots of rocky caves; no plants.
Of course, you should check the details of the exact species before you buy, as cichlids vary a lot, even in the same family.