So, I agree with you that life is likely out there and in abundance given the vastness of the universe. (Even if I think it’s very equally improbably that advanced intelligent life has visit Earth 😂). Refer to Drake’s equation that whittles down that high probability to possibly 0.

That said, your question of “what would it look like” has been addressed by Carl Sagan in his old Cosmos series. Considering that humans and a tree share 25% of the same DNA yet are unrecognizably different, you can safely conclude that an alien species that shares 0% of our DNA (or any DNA at all) would be entirely different. So forget those movies where humanoid aliens are bipedal or look like giant insects!

So Sagan and other xenobiologists rely on convergent evolution theories — like why a shark and a dolphin have similar “flippers” — to speculate on life forms that rely on various environments (gravity, water, temperature, atmosphere, orbit and rotation, radiation, primary star type and distance, living energy transfer, available minerals, etc etc etc) yet might have evolved similar solutions to life here on Earth.

…or it would look more different to us than a virus or amoeba does.