I did a photo of the night sky and wanted to find a constellation on it. I've suggestion that it is Delphinus constellation. Could you please help me figure it out. Also, I'm curios about good way to figure out constellations on a photo.
The object inside the red circle is indeed The Pleiades. Note that it is not a constellation, it is an open star cluster located in the constellation Taurus.
A good way to identify constellations in a photograph is to use the Astrometry website, where you can upload a photograph of the sky and the application searches for the constellation it belongs to.
These are the Pleiades. I verified it comparing your photo with the Stellarium app.