A simple possibility: Use the Garmin program Basecamp (free), use either a map from Garmin of your Area (costs money) or a free osm map (p.e. a map downloaded from http://garmin.openstreetmap.nl/ set a waypoint to one end of the street and another to the other end of the street and calculatein Basecamp a route between the two waypoints with one of the offered activity profiles, but not the profile “direct”. Normally the route will follow the street exactly. If not you have to set intermediate waypoints. In the properties of the route the route lenght is given.
May be you look first to the osm map in the internet: http://www.openstreetmap.org/#map=14/-15.7982/-47.9186&layers=Q to see if you find the streets you want. (This map is zoomable with the mouseweel and shiftable with the mouse.)
Yes, it is possible. Downloading so much data via Overpass Turbo may be a bit to much for this service.
Here’s another possibility:
Download the Shapefiles for Brazil from Geofabrik: http://download.geofabrik.de/south-america/brazil.html
Extract them
Open roads.shp in QGIS
Download the boundary for São Paulo: https://osm.wno-edv-service.de/boundaries/
Open the boundary shapefile in QGIS
In QGIS: Goto Vector → Geoprocessing Tools → Intersect → Choose “roads” as Input vector layer and “boundary” as Intersect layer → Create new shapefile