If you're interested in keeping corals then starting with mushrooms and Zoanthids is the best idea. They aren't too difficult to keep, don't require much lighting, and are fairly hardy.
When it comes to keeping corals there are several things to consider. Corals need specific lighting which could mean anywhere from low to extremely high in intensity depending on the species. Aside from that they require medium to high water flow, again depending on the species, and may require supplementation of Phytoplankton and mysis or other brine shrimps.
Many corals feed at night time so you will need to dose the tank when the lights go out for best effect.
Now, the most important part about keeping corals is stability. Not only does your water need to be within a specific range, but it must remain constant within those ranges.
Keeping corals can be very difficult, or fairly easy, depending on the the type. Having a solid grasp of maintenance and keeping good water quality will increase your potential for successfully keeping these animals.
Stick to the soft corals and mushrooms for now, leave the hard corals for when you have much more experience.
I have had my tank running for about a year and a half and I am just getting to the point where I am getting ready to start stocking some coral species. No Acropora at this point, I'll throw some mushrooms in there and I will be trying an anemone. But by now I have learned quite a bit and I am not stocking anything that I am not absolutely sure I can handle. I have a good track record with stability so that is what is prompting the new additions. Well, that and a new lighting rig.
HTH,
Aaron
