The picture shows a simple 4-layer classical neural network. How to transform it into a corresponding QNN? And design the corresponding quantum circuit for training, adding the input data set element size is within 100？

First, I use quantum encoding technology to convert angular encoding into a phase representation, then how should I choose ANSATZ and design-related parametric U gates? In the last measurement, what I read was actually the parameterized angle value correct? Then iterate on the parameterized angle value to get the best angle. But f(x,theta), does theta optimal represent the optimal output result x?