How to set system properties in substrate blockchain for private network?

I am deploying my own private blockchain using the substrate code. In which how to set the token decimals and token symbol while deploying it?

Solution

These parameters are set in the node's chain_spec.rs in the template code and an example from polkadot code that ingests a JSON file for a specific chain (examples)

To get this generated for you automatically that you can then customize, build the node and then follow the flow outlined in the cumulus workshop to get a plain chainspec, edit as you see fit, and then generate a custom final one that you can use when starting your nodes.