The fish you want to get are both livebearers meaning that they give birth to live young and very frequently may I add.. I suggest only getting 3 or 4. Make sure to have more females than males. It may seem like it's not a lot but in time they will give birth to much more. You will have your tank overcrowded with them. But I think that you would be better off with getting only males at first, especially with guppies because the males have longer fins that have loads more variations than the females! I think this would be the best option for you right now, just so you can figure out if you really like the fish and wanted more.