Well, I kind of wanted to make this entertaining topic so that beginner fishkeepers can view this topic to not follow any of the advice, I'm hoping it worksHowdy, and welcome to MFK.
While this might be entertaining, why don't you share good advice and turn your first thread into a productive and helpful contribution to the hobby?
What do you wish you had been told by fish store staff instead of nonsense?
Some person at the place I work at bought freshwater angelfish and celestial goldfish together, all for a 30 gallon tank :/