>I use 'SQLSTRINGCONNECT' to etablish connection to my database (mysql) . How can select tables

Once you get a establish a connection you get a positive number as a return. That is the file handle that you save in a variable or object property.

You use that handle when doing a query to the remote database to return data.
SQLEXEC(nHandle, cSQLQuery, cCursorName)

If the query was successful (returns a positive number), you now have a cursor (using the name you chose) with the results which could be 0 or more records.

This you manipulate as any other VFP table:
Select MyResultCursor
BROWSE
USE MyResultCursor
etc.