sitting

As far as what I know you don't have to make your dog sit before you go on walks, you do have to wait about half an hour though before taking your dog for more than one walk. To get your dog to sit you need to place the hand icon on your dogs head and drag it down, there should then be a lightbulb icon in the top right hand corner and you need to verbally say sit into the mircophone. Do this several times and your dog should learn the trick.
One other tip I have found while walking is to wait for your dog to turn and face you while standing still slightly moving his paws and give the leash a tug gets him running faster. Hope this was useful XD