One possibility is silicon, which can form complex molecules, as carbon does. But the compounds it creates are not as stable as carbon, meaning they can fall apart easily. That's why most scientists reject the notion of a living world based on silicon. NASA image . Carbon has a unique chemistry that no other element does, and because of that, it is certainly the best element for life.
Life needs water for the chemical reactions that produce organics.
Bunches of carbon molecules can lie side by side on dry land without ever reacting. But stick them in water, and you get action. You need energy. Living things can't arise without energy to fuel the reactions. On Earth, energy from sunlight can do the job.