You can have a non-drilled tank and still have a sump. I do. You just need an overflow box. Drilled tanks are definitely the way to go though! Welcome.
Welcome to r2r. I’m about a year into the hobby and my wife is just now starting to really enjoy what we’ve built. She’s helped me build everything but is finally starting to see why I’m so fascinated with our box of water. Glad you are both doing this together, it makes it soooo much more fun. Good luck, be patient and we all run into issues so don’t let them discourage you, just look at them as learning opportunities. Everyone here is eager to share their knowledge and experience so never hesitate to ask any questions you have.