Unless you are a database expert, this is going to be hard. Databases are tricky to get right and losing data is easy, so I will recommend to go with something

Unless you are a database expert, this is going to be hard. Databases are tricky to get right and losing data is easy, so I will recommend to go with something as standard as possible. I would normally recommend just to use a managed product (Postgres/MySQL on any of the cloud options, and there is no lock in since it is still the same raw DB). You will be able to sleep better and once you are a DB expert move away from managed DB to self managed DB.