On the Job Training (OJT) is very popular. It’s likely you will end up living with the hubris produced by OJT. It’s not you, it’s a mess. So what can be done?
Create an independent project that performs the minimal essence of your hubris. Use this to experiment, test, revert (commit this to a source control system somewhere). It will be much faster to build & change than the actual project. And the learning will be far better!
A major problem with OJT approaches, is that it’s easy to make bad/incorrect/poor choices. As implementation moves along, the errors compound. Your reference implementation will serve as the baseline to unravel the compounded mistakes. If the project has had one OJT after another person in this role, it quickly can become a quagmire.