Can we buy regular AA and D batteries in Turkey and Greece?

I do not see why not, as batteries are batteries around the world, or supposed to be. But i will caution that these may not be the same batteries you buy here. We grabbed a package of AAAs in Budapest and discovered they were just barely shorter than ours and did not maintain contact in our camera properly.

You also may want to delete your duplicate of this post.

You can, but be prepared for them to be more expensive than in the US, particularly if you aren't able to take time to shop around or to travel to a cheaper store.