Becoming Catholic
You would be most welcome to join the Catholic Church! It may be a comfort to know that the word "catholic" means "universal". This means everyone who accepts the teachings of the Church and is properly prepared can become Catholic, and is most welcome.
Generally, a person who wants to become Catholic must first go through a program called OCIA (formerly RCIA)
(Below is taken from Catholic Answers):
OCIA, formerly called RCIA (Rite of Christian Initiation of Adults), is the Order of Christian Initiation for Adults. This process involves adults and children who have reached the age of reason (age seven), entrance into the Catholic Church. OCIA was established by the Church in 1972, but this catechetical process welcoming converts began the exact day the Church was instituted at Pentecost. In fact, in the 2nd century, Saint Hippolytus wrote about a three-stage process for becoming Catholic for converts. If you’re ready to start OCIA, reach out to your local parish to get connected. The classes typically start in September, with Confirmation occurring at the Easter Vigil, making it roughly a six month commitment.
At the Easter Vigil, those who are not yet baptized receive Baptism, Confirmation, and Eucharist, while those already baptized are received into the Church and confirmed.