'hold it'???



I just moved from a house to an apt. (marital separation).........and this is the situation:

My wonderful dog Scout is confused about this going potty/poop while on leash (in the past a leash has always meant 'walk', 'car', 'beach', or something fun).
She also gets really distracted by other dogs, squirrels, people and won't go.
ANY tips that would help will be appretiated.............like how long should I stand there waiting? If she doesn't go, how soon should I take her back out? Any good commands that might help?

ALSO **very** important: how long is it realistic/fair to expect her to hold it? (I work)