The attached photo is clicked in a professional DSLR camera. How can I get a similar effect of blurred lights in an ordinary digital camera, Or How can I edit a image later to get this similar effect?
This effect is simply achieved by having the background out of focus, using a wide aperture. This is known as "Bokeh" - see https://en.wikipedia.org/wiki/Bokeh
This can be achieved with a phone / or compact camera, but you will need to be quite close to the subject, and the background must be a good distance away. Exact measurements cant be given as it will vary depending on the lens/sensor arrangement.
This can be emulated in post but often looks terrible.