does such a thing exist?
Phone Catechism? Only if there is a priest willing to do it. I knew a priest that did pre-Cana/marriage preparation classes over the phone because he couldn’t always meet in person with the engaged couple, as he was a traveling missionary priest.
Maybe someone here knows a priest that can help you based on your current circumstances.
What you really need for now is the Catechism book, My Catholic Faith, and then hopefully you can find a priest to answer any additional questions you may have. Maybe start writing down those questions that you are needing clarification on too.
Don’t forget to continue praying for and asking God for guidance.