OK
Movement phase: You can go 6"
Shooting phase: You can shoot OR run. If you run, roll a dice and move that many inches.
Assault phase: Normally if you run you can't assault. If you have the fleet rule you can! Simple!
There's more to it than that, of course, but if you're playing at your
FLGS they should be able to talk you through it (esp. as its your first game.)
Hope it goes well - and welcome to the hobby!