Can I find out someones address/email/number with just their first name, age and their country?

No. It will be like looking for the proverbial needle in the haystack. There could be lots of people with the same name and age in the country. How are you going to distinguish between them? You can cut down the odds if you know the place where they live, and again if you know the district. Only then will the family knowledge become useful. Dutch people are very nice, as I've been friendly with several of them. If you knew the town you could write to the Mayor and ask him to find them, giving him all your information. I was successful doing this when looking for an acquaintance.