Since your just starting out you really don't want to deal with any mean fish...I'd get a good size school of tetras, 7 or so... a school of 6 cories to patrol the bottom for uneaten food and that leave you with enough room for a larger centerpiece fish that is not too aggressive to the tetras or cories... maybe a single gourami, betta, With this set up you could also have shrimp I would think but you need to be careful about what you center piece fish is then.