Regardless, the central bank lends the initial money supply with some interests, meaning that a commercial bank already started with debt.

In order to cover the expenses (inherent debt), they increase their interest rates when lending money to either businesses or individuals.

FED does support a fractional reserve system (which isn't necessarily a bad thing if under control), meaning that they can predict (to some extent) how much money will get printed over a specific period of time.

Am I getting something wrong here?