How to relate animations to characters that are downloaded from different websites?

I’m new at using Unity and just started making a third person game
My problem is that I don’t know how to animate my character with some animations from other websites without using because it doesn’t have the animations that I need for my game so any one would give me some steps to follow or some hints that would leads me to the right way of doing it??

you can import the characters into a photo program like Photoshop or Gimp and make the animations yourself. I have taken characters and broke apart put each body part arm,leg,torso etc… as separate images and create bones in the unity sprite editor. there are a lot of good vids on animating characters on you tube. you can look at blackthorn prod his are pretty good but there are many.