Can't find someone on facebook..?

[Jenny]

I met some awesome new friends last week on a missions trip,(the trip was in AL and all of my new friends aren't from anywhere near me) and they all said they had facebooks. I tried looking for them but can't find them on facebook. Their names are like "John Smith" (that was an example, im just trying to get the point across that they have very general first and last names), so many other people have the same name so that means there's a bunch more people on facebook which makes it harder to find them. Any advice on how I can find them?