Starting SMR setup and simulation for neutron shielding optimization

Dear OpenMC Community,

I am just starting my journey of working with OpenMC, and I want to simulate the Small Modular Reactors using this tool. I am writing to ask for your recommendations on where should I start from. What files do I need? Where to get the parameters from? Where can I find the examples of SMR codes?

Specifically, I plan to use OpenMC for neytron shielding materials optimization.

I already found papers on this topic, though it is hard for me to start actually coding.

Thank you in advance!