There is no such thing as "being born on a cusp." There are cusps in astrology, but they are the dividing lines of each of the 12 houses. My husband was born on April 20th, and he was a Taurus, and I think most years it works that way. Since every planet you have is in a sign, you could have Mercury or Venus in Aries, and that's why you exhibit Aries traits. It is different each year--that 21st of the month to 21st of the next month--is a fallacy. If you want to be positive about your Sun Sign, Please write back and remind me I told you to do this--give me the 4/20 again, but tell me the YEAR.
But let's go with Taurus Sun people. Venus rules them, so have a kind and gentle way with people. They are polite and sensible. They don't talk a lot unless they really have something to say. You are a good and loyal friend, and probably have friends around you knew since childhood.
The Capricorn Moon represents your emotions. You hold them in, but some mistake that for thinking you are not emotional, when you really are. Your family means a great deal to you and you need to have security in your life, or at least be working towards it. You are ambitious and a hard worker, as Capricorn is a leadership sign. People accept you as a natural leader. Cancer is also a leadership sign, and the rising sign is the way you appear to others. This actually does allow you to show your feelings more. Cancers are very emotional, sensitive, creative, nonjudgmental and generally well liked by others. They also are close to family. So the Cancer in you makes you a bit more chatty, which I think is good here.
I see you as being sort of conservative, but willing to fight for what you believe in. You are nurturing and truly care about others, though with the Taurus and Capricorn in you, you show that in practical ways. You are likely to write a job resume for a friend, or plan a group vacation and keep track of all the details.
So you are an Earth/Water person, and could easily get along with other Earth and Water signs. You may have Mercury or Venus in Aries or a planet or two in Leo, both fire signs, so can be attracted to air signs or other fire signs. I think it's a nice combination. Best Wishes to you, and if you want me to look up the sun to be sure, come on back!