J'ai = I have.
Je suis = I am.
That said, not always when you would say "I am" in English, is the French translation Je suis. The French say, e.g., I have 20 years (j'ai 20 ans). There are other examples, but they are, all in all, exceptions. Mostly, être and avoir are used as they are in English.
Don't get hung up on this, just continue studying. It will all fall in place eventually.