Hey,there im a new time fisher person? and dont ask **** about my tank i don't have one yet ); but i dont want a boring aqurium you just watch you know what i mean? so i want to have a fish that breeds a reasonable amount NOT GUPPIES but i'd like them to be easish care but not "not even tryn" so can you please help?

ps. I want a fish that is
-colourfull
-small
-sold easily
-easy to breed

pps im gettin a 20-30 gallon tank


Thanks in advance :D