Opened the shop
This is the only one that measures your announcement rather than your shop. If it is low, the problem is outside the Mini App: the post, the time of day, or the fact that people cannot find the button. Fix the entrance before you redecorate the room.
Reached the cart
The gap between opening and adding something is the first screen doing its job or not. The usual cause of a wide gap is the first row of products: whatever sits at the top decides what people think the shop is. Put your best seller there and watch the number move.
The second usual cause is price without context. A price with no size, no material and no delivery line beside it is a number a stranger cannot judge.
Finished the order
People who reach the cart and stop are the most expensive ones to lose, because they were ready. Look for anything that asks them to leave the chat, anything that fails silently, and anything that makes them guess about shipping. A cart that cannot be priced is a cart that gets abandoned.
What they opened first
This is the number that changes your catalogue rather than your funnel. The product people open first is what your audience thinks you sell. If it is not what you want to sell, either the shop is arranged wrong or your audience came for something else, and both are worth knowing.
What to ignore for now
Time on page, number of sessions, average items per order. They matter when there is enough traffic for the average to mean anything. Early on they move for reasons that have nothing to do with you, and chasing them wastes the week.