Beginner in 3d modeling(& everything)

so I'm planning on going to school for jewelry in the fall. My dad is supportive of this and is working on a workshop that I can use in the future for my future work. Thing is, he wants me to learn some stuff before I go to school. He wants to get a 3d printer and for me to learn 3d modeling, which is something the school will have, and it's nice to have a head start. I'm a complete beginner in professional jewelry making. Though I do look around to get some knowledge for the future. I'm pretty sure in jewelry, it's resin 3d printing. Though I am confused so I will ask here. Do I get a resin printer? If so, what are beginner and good priced ones? what are all the things I need? I know I don't just need the printer. I'm planning on buying rhino 3d since I've seen that's the standard and what my future school is using besides matrix gold. What's the best ways or sites to learn it?

I looked around and if I'm understanding this right, the file I make on 3d software gets sent to a casting house. Do I print a resin version first to make sure it comes out right before I send it?

Also I'm kind of nervous, do I need to do a lot of research on structure before I try to 3d model? Or just wing it and learn from mistakes?

Im just a complete beginner trying to learn😅 Any learning resources like sites, books, etc would be helpful.

Try to explain in simple terms because I don't know all the lingo yet. Basically what do I need to learn and know, I appreciate my dad's support and want him to know that, so I really want to learn all that I can.