On Collision go faster

I trying to make a game when the player walks into the power up it makes them faster does anyone have a Java script that can make the player faster?thanks.

Well, you should have a script that controls your player, with variables that you can change to speed him up. F.e. the Standard Asset First Person Controller has “Max Forward Speed” that you can change from a script.
On how to do that: This tutorial has exactly what you need: powerups and picking them up.

You must have a function in your script called on collision enter

If you dont it does not work