You use "some ___" to talk about an amount, or a number, of something, that's not specific. For example:

I met some really nice people in Finland.

This means that you met more than one nice person, but it's not said how many.

You can use "some" with countable things, like people. Or you can use it when talking about something that you can't count. Like when you're making someone a cup of coffee, you ask:

You want some sugar in it?