Go to https://www.openstreetmap.org/ and make a right-click on the object and select »object request«. See if it’s an node, way, relation or area and copy the id in the parentheses.
Open https://overpass-turbo.eu/ and type:
Node (Single Point)
(node(265576692);>;);
out skel;
Way (Could be a outline of a building as well)
(way(24448328);>;);
out skel;
Relation (A relation is a group of elements. Could be administrative boundaries)
(rel(4773565);>;);
out skel;
Find more information here: https://wiki.openstreetmap.org/wiki/Overpass_API/Overpass_QL