Porto - Neighborhood To Rent Apt for 1 Week

Greetings fellow travelers,

My wife, 5 year old daughter and I are heading to Porto for a week in May. Renting an apartment usually works best for us and there appear to be plenty on VRBO. Three questions we could really use some guidance on:

1. What neighborhoods are safe, walkable, and not too far from a market, restaurants, shopping, etc.?
2. Any recommendations on an English-speaking guide we might hire for a day of orientation, sightseeing, etc?
3. Any recommendations on trustworthy VRBO alternatives.
   

Many thanks!