Start with the basics of SQL.
I.F. Astakhov, A.P. Tolstobrov, V.M. Melnikov "SQL in examples and tasks". I started with this training course. Then you can read Martin Gruber - Understanding SQL. Start learning with simple queries and tables. Then gradually you will begin to understand how and what.
Then refer to the documentation MySQL programming language. This is more than enough to solve a specific problem. Watch webinars, read thematic forums.
UPD: I forgot to write that it would not be bad to know English. Because Query language is very simple and is constructed as a common phrase. Triggers, cycles, branchings - all this will come with experience and reading documentation, forums, articles ... In general, the eyes are afraid, and the hands are doing (n) Russian popular saying.