Does it matter which country I am in to pursue this dive?
 
The best news about studying SQL is that no matter where you are in the world, you can quite easily improve your SQL. As long as you have access to a laptop, you will be able to practice your skills, improving every day.
 
The bottom line, the answer is no: it doesn't matter at all which country you are in. Wherever you are, you can start learning or improve your SQL. Truly, these days, if you want to become an expert at SQL, and you aren't an expert yet, the only reason is: "YOU ARE LAZY". 
 
Remember the Break Diver's Creed: No Rules. No Excuses. No Regrets.