If you want to smooth out the camera movement only, attach it to a Springarm and Enable Camera Lag.
If you want to move the actor smoothly, you’ll need a slightly different approach:
The input sets a desired value and the interpolation node will try to reach it based on the Interp Speed. You will need to adapt it slightly to use the appropriate forward/right vector, of course. This is just an overall idea.
You can also combine the above-mentioned interpolation with camera lag for for utterly-buttery smoothness 
To get it to work like shown above, you’ll need to add proper inputs:
