Well, there's no direct and easy way to calculate walking speeds, it's trial and error - but in DBPro your command could be as simple as:
MOVE OBJECT Obj,spd#
Spd# being the speed your character shall walk - I'd look into a more mathematical method, but for messing that's an ideal command to start with.
Just have the camera follow your character, rotate him a little each time and move him forward, experiment with different speeds and you should have him walking in a circle quite realistically.
Personally, I would practice animation a lot rather than trying to follow too many tutorials. Borrow a camera and film someone walking then try to replicate that - adding a little exageration to their limbs, it's actually quite easy if you can break it into a dozen or so reference images, which you'd try to replicate as keyframes in your animation package. There are some techniques that can be followed, like little systems that can help, but I find trying to be too regimented leads to overly exagerated movements, really a normal walk is very subtle and quite difficult to replicate. Having an assistant might be a good idea, like someone who's happy to let you study their movements and film them - it's like they get to be the star in the game, should'nt be too tricky to find a volunteer.
Van-B

Put away, those fiery biscuits!