Learning about substrate
The Creditcoin blockchain is built on the substrate framework, which provides most of the underlying blockchain functionality (P2P networking, block production, block finalizaiton, RPC server, storage, etc.). This allows us to focus on the functionality specific to creditcoin and additionally we benefit from existing tooling developed for the polkadot/substrate ecosystem (such as the polkadot explorer, polkadotJS, telemetry, etc.).
Helpful resources
The official substrate documentation provides a good starting point, I would recommend (at a minimum) reading through all of the material in the Learn section.
That should give you a rough understanding of substrate's architecture, and how the pieces fit together.
For learning about FRAME and best practices, the substrate repository has a bunch of pallets of varying complexity that serve as good reference points. For starters, the sudo pallet is fairly small and digestible.