Relational databases are built on the mathematical model described by the relational algebra. There is approximately forty five years of literature, thirty five years of wide-spread use, and three open source projects: Postgres, MySql, and SQLite with approximately two decades of use.
NoSQL does not have a mathematical basis. It is a term invented for a conference about non-relational databases. There are mathematical bases for many things that are called 'NoSQL' and good products and technologies behind them. But there is no commonality between them.
SQL unites relational databases and makes the practical differences between relational databases differences of features rather than architecture. NoSQL databases differ in architecture: key value stores versus graphs versus semi-structured data.
There is a well understood and common meaning of 'database schema' when referring to relational databases. While a particular NoSQL database might have a strong notion of schema (or might not) it will differ from NoSQL database to database and among them the common notion of schema is very abstract at best and almost certainly grounded against the definition of schema in the relational database world.
In terms of learning, the relational model seems like a better starting point: better learning resources, mature products, mathematical structure, and constituting the common basis for discussing databases in general.
On the relational side I'm probably biased toward Postgres as a starting point because there is more signal to noise than with MySQL. It's not that there's anything wrong with MySQL it's that the success of the LAMP stack means there are lots of 'How to build a potato chip rating website with MySQL' blog posts whereas with Postgres there is a higher likelihood of useful technical detail.
That's not to say that a resume site needs a relational database (or a NoSQL database). Files on disk would probably work and that might be an interesting alternative exercise.
Frameworks like Ruby on Rails abstract away the a lot of the complexities of schema design with objects and Classes. There is a full relational database schema in a Rails application and the programmer pretty much is discouraged from touching it directly.
So that's another approach.