you are correct about "t’u" and usted. Usted is the formal you. We don't have a formal form of you in english. But you can use usted and t’u for the same person. But the conjugations change depending on which word you use.
I guess that "vosotros" and ustedes would work for each other. Because vosotros is basically "all of you" and ustedes is the plural of "you". But remember that conjugations change depending on which form you use!
So haber would be:
Yo - he (CORRECT)
T'u - has (CORRECT)
él (masc.), ella (fem.), usted - ha
nosotros - hemos (CORRECT)
vosotros (apparently old fashioned ;0) ) - habéis (CORRECT)
ellos, ellas, ustedes - han
you are on the right track!! awesome job!
bein!