If that's the case, a good resource would be to look at the developer guides for popular open source databases, such as the one for PostgreSQL[0], which will give a guide to how those databases are put together.
* Think about how you want to read the data. This should inform how you design the storage.
* Understand concepts before you shortcut them. For example, synthetic keys are great, but be sure you know what the real primary key is for the data. NoSQL storage can be fast but you might pay in storage size or other flexibilities.
* Find sources of truth and use them to validate your learning. Build your intuition from fundamentals.
* Start fielding newbie questions on the topic. Appoint yourself expert-in-training.
* Learn PostgreSQL and participate in online discussion about it. This might be the most fertile OSS community I have found, pretty much ever. Highly recommended.