Creating objects that interact combined with animation

I’m trying to create a couple objects that interact with each other, when the objects get close enough to each other they trigger animation such as particles shooting off one object onto the other. But only when they are a certain distance from each other. I would like there to be some interaction with the objects as well, if you push the objects closer together they repeal. I want to let the player pick up one of the objects in VR and be able to move the object in the player hand closer to the other object which would trigger the interactions. Any help with this would be amazing! Thanks!