There is a couple of things you must know about the aquarium. First of all we must see how big your tank will be. From my experiences the bigger the tank is, that's better because small tanks need more care like water changes, gravel vacuum, controlling water Ph ...
Then we need to plan where we want to put the aquarium, we don't want to put it in a direct sunlight because there will be big algae growing for the sunlight, so less sun better.
Next is the gravel. Generally the is a rule a pound of gravel for a gallon, but mostly depends of you how much you wanna put. Then we need to have good filtration you can ask at your pet store for details because it depends from the tank. Another thing is you must have hood and light on the aquarium which must be on from 8-10 hours/day for a proper live plants care and it's good for fishes.
More about fish care in part 2