Something I learned from the Jesuits when I was a boy: When in doubt, confess.
You will never go wrong discussing your behavior with the priest in the Confessional.
Of course, this can be taken to extremes: if we took even our slight doubts to the Confessional, however unprobable they might be, we would be being rigorists, and would be applying a moral analysis to our behavior which has been condemned by the Church.
However, in this case, and for the OP, I think I would recommend going to Confession, simply because
they need to begin to form their conscience.
Leigh, if your priest or priests can be seen as being solid and reliable, I would certainly ask them to help you understand the principles behind some of the things you have questions about.
As for not telling your mother about your becoming Catholic, and whether this is sinful: it would be sinful to not tell someone something they have a right to know.
For example, let’s say there was a 5 foot tall space alien living in her attack. Well, I would say, in justice, she deserves to know about that, especially is said alien is posing a threat to her life.
On the other hand, she may not need to know a great deal of things about you; and yes, whether or not you are Catholic might be one of them.
Your being Catholic might be something she has a right to know under conditions that she’s clearly established with you. For example, let’s say you live with her, and she’s told you that the only reason you’re allowed to be there is because you’re not Catholic.
As someone else has asked: it would be relevant to know if you live with your mom.
Likewise, I don’t think that your not telling her just yet is somehow denying God: it is simply finding the time and the place to communicate with her, and that is totally a judgement call.
You would be denying God if she came out and asked you about your religion, and you refused to tell her the truth about it.
… and WELCOME HOME!!!
After your baptism, you were totally a LIVING SAINT, having had all of your sins washed away, along with the temporal punishment for them. How cool is that?!
