Welcome to keeping freshwater!!!! Whatever you do, do not be like me lol, when I got my first aquarium I immediately started keeping a couple Red Belly Piranhas. Thankfully none of them died, but if I could go back I'd go with something else. Hmmm for a beginner, kind of depends on what catches your eye and what kind of idea you have for your tank.
Can you give us more insight of your tank, like what kind of filtration, kind of lighting, heating, etc.... this will help us in recommending which way to with your tank. Also what kind of tank do you have in mind?!?! For instance, are you wanting to go with a planted community tank, non planted aggressive cichlid tank, etc.....