Help Animate my NPC's

Hey guys, I am currently working on a VR experience and can’t figure out how to animate a figure without controlling it by using keystrokes. In the VR experience, the user will only be able to look around with a camera. I have created a few characters in Mixamo Fuse and would like to have them walking around/running/falling in the VR scene at a specific time and place in the scene. Could you give me some pointers as to how to do that? I tried using animations from Mixamo’s online animation maker, but for some reason, I cannot move the animations to different times in the animation window, nor can I take all the animations I downloaded and put them onto a single animation timeline or edit the Mixamo animations in any way. Thanks for your help!