For example, I am from Turkey. Are these licenses valid for me?
TL/DR: Yes, Open Source licenses are valid in Turkey and nearly globally.
Open Source copyright licenses are based on copyright law. While each country has its own copyright laws, there is an international agreement (the Berne Convention) in which countries have agreed to have certain commonalities in their copyright laws. Turkey is one of the signatories of that convention.
While there are still differences in copyright laws (like if moral rights are recognized in their own right), the functioning of the Open Source licenses is based on the common pats of the copyright laws and thus they are effective in all countries that follow the Berne Convention (which in nearly all countries in the world). For the countries that don't follow the Berne Convention, you would have to check their specific laws.