I have some postcards of the new york world fairs 1964-65, mint condition and unwritten on, also lots of other postcards from all over the world all dateing back to the mid 1960's are they worth any thing

You can find some '64 Worlds Fair postcards for sale here through the search function. They seem to be offered at $3-7 each. This may or may not be "what they're worth" (None has a bid, but that's what they're offered at.)

While not exactly what you want to hear, it's really impossible to say what your other cards "are worth" (meaning how much someone would pay you for them.) The question is too broad. Searching for cards like what you have here on Delcampe might give you an idea of what price they may be offered at. Do you live in a city with a postcard club or dealer(s)? This would be another way to find someone to actually look at the cards.

Postcards aren't like stamps or coins where you can just go to the catalog and look them up.

I have some postcards of the new york world fairs 1964-65, mint condition and unwritten on, also lots of other postcards from all over the world all dateing back to the mid 1960's are they worth any thing