Get all city information (roads, buildings, ..etc) in OpenStreetMap via Overpass API

Overpass API is not really the right tool for querying large data like all buildings and roads. It is rather suited for making specialized queries like all postboxes in an area.

For rather large and complete extracts of OpenStreetMap (like in your case), I recommend to download from Geofabrik or OSMaxx.

You can do a one time download via https://www.openstreetmap.org/export#map=14/43.9402/4.8096 -> then click on the "Overpass API" link. This area is small enough to be downloaded via Overpass API, the resulting XML will be around 100MB.