I recommend you to download the
documentation and study section 12.1
Data Definition Statements, section 12.2
Data Manipulation Statements and additionally section 10.1/10.7
Data Types. While you are exercising, look up the
syntax reference.
After a while, do the same with PostgreSQL. Why? In contrast to the MySQL documentation, you will find a real
handbook. Why else? Because you avoid a habit of typing out code and advance your skills in dealing with declarative programming.
Concerning the declarative paradigm in general: Consider literature that boosts your beginner's experience. I recall Joe Celko's
Thinking in sets to be well-written introduction.