It is likely that all kinds of life forms exist, from those similar to ours and those based on cellular and chemical combos we can’t even perceive.  However, when searching it can make sense to look for conditions similar to ours:

“The ratio of elements on Earth has led to the chemical conditions ‘just right’ for life,” said lead researcher Brad Gibson, an astrophysicist at the University of Hull in the United Kingdom.

Here is also an intro to a video examining these properties throughout the Milky Way:

Embark on an astounding journey across 100,000 light-years to witness key moments in the history of the Milky Way. Using cutting-edge science, National Geographic constructs a 3-D state-of-the-art CGI model of our galaxy. Gaze into the heart of the Milky Way on the hunt for super-massive black holes. Witness as stars are born and die. Fly out and above the plane of our galaxy to understand its true shape and scour its dusty spiral arms for the possibility of life.

thanks to space.com for the great info

https://www.youtube.com/watch?v=aNV1Q–R7-A