What your first version actually needs to prove
The first version of a product has one job: to show whether people want it. That usually means one core flow done well, sign-up, and enough of an admin side to keep it running. Everything else, from referral schemes to advanced settings, can wait until real users tell you it matters.
When you send me an idea, the first thing I do is help you cut it down to that core flow. It is the cheapest decision you will make, and it is the one that most often saves a founder's budget.