Lady Gaga and her fiancé Michael Polansky are officially parents! Page Six revealed Friday that the original “Mother Monster,” 40, and Polansky, 42, have privately welcomed their first child. The couple — who began dating in 2019 — was spotted stepping out for a walk with their baby in Northern California, in photos exclusively obtained by Page Six. Amid the news, here’s everything to know about the new father and his life with the “Bad Romance” hitmaker. He’s an entrepreneur Polansky is an entrepreneur who co-founded Outer Biosciences, a skin health company, in 2022 with Gaga. He’s also behind investment and venture firms including Avos…