Names for people are fairly easy to come by and some are mentioned above. Place names are more challenging. I have two favorite sources: historical maps and Wikipedia.
Historical maps are doubly useful (I have lots of sources for Europe, very little for elsewhere, but have seen enough to know such collections exist), First, they give the old names for places. And if you're not writing actual historical fiction, you can just use them for inspiration without worrying if they're in the right place. Just linguistic consistency. Which brings me to the second use; namely, that place names change over time. So, a map of central Europe in 300 AD is going to have different names than one in 1300AD. For my writing, that will matter.
The other source is Wikipedia. There I use it mainly when I've settled on a particular place that's going to figure in a story. Very often, though not always, Wikipedia will provide historical names as well as the name in the other cultures that had figured in that place's history over the centuries. So, if you're looking broadly, this second source is less useful, but may prove so later on.