I believe in God because If i didn't I wouldn't have a feel for my purpose on earth. Without God why would my Grandfather have wasted almost 40+ years preaching and giving his life up for him. Without God there would be no good in this world, because the Majority of us Believers in Christ want Goodness on earth and Peace. You want to find God for yourself read the bible, and it's dumb for me to try to explain it to you, why you ask, cause it's not my job to tell you what to be. Rather you pick up the Bible and read it for yourself. Go to a good bible Based church, preferably a non-denominational Christian Church.
Your 2nd question to answer why we refer to God as "HE". There's God the Father, God the Son, and God the Holy Spirit. He is never called God the Mother or God the Mother. Jesus was God Manifested into Man, he wasn't Manifested into a Woman. I highly suggest you read the bible, because I don't want to have to teach you, and you just go along with what I say. Reading and Asking Jesus to allow the Holy Spirit to help you comprehend the bible is much better than me telling you the way.