Use the analog stick to control walking and running

How would I go about blending between walking and running using the controller’s analog stick? Meaning I push the stick halfway and the character walks and when the stick is pushed all the way the character runs.

The movement controller will handle the speed for you. If you’re max speed is 500, then pushing the analogue stick half way would give you 0.5 * max speed, which would be around 250.

For the animations, you should look at Animation Blending:

I believe that the 3rd person sample that comes with the Engine also has examples of animation blending which you could look at.

theres also the following tutorial series by epic