The bridge is real. The Pont Saint-Bénézet at Avignon lost most of its arches to the Rhône centuries ago, so it now stops partway across the river, which only improves the song - people have been singing about dancing on a broken bridge since the 1500s.
The line to steal for real life is - "go like this". Faire comme ça is how French handles "do it like this / like that" in everyday speech, and the song drills it with gestures attached: the gentlemen bow, the ladies curtsey. In the 1870 songbook this is printed as a "chanson mimée", a mimed song, with the stage directions included.
One small wrinkle: the version most people sing today says "l'on y danse, l'on y danse" in the second line, where the 1870 text we print has on y , l'on y danse. Both are traditional; we print the older one and you may sing whichever wins in the room.