Welcome to RCIA! Know that you are not committed in joining the Catholic Church just because you attend RCIA. It is a discernment process, though it sounds like you have your mind made up. In either case, that’s great! I invite you to begin to attend Mass as often as you can. You can fully participate in all parts of the Mass EXCEPT Holy Communion. I suggest for starters, if you can, to attend and occasional daily Mass. They are shorter, usually 30-45 minutes. There are less people, less distractions, and will give you a chance to experience it unhindered. If attending Sunday Mass is problematic with your family I encourage you to try going to the Vigil Mass on Saturday’s for starters. Invite your family to come with you. Share your journey with them as much as you can. Let them see the transformation taking place in your life, and there will be one. If your intention is to become Catholic, I see no reason to continue attending your protestant service unless it is problematic with the family. Furthermore, since you are unable to receive communion within the Catholic Church because you are not in full communion with it yet, I would strongly urge you to not take communion in the protestant church as well for the same reasons, they may not see things that way though.
If you have any questions feel free to ask, I wish you well on your journey and shall pray for you and family during this time.
God Bless You!