We've been discussing universal origins in the light of scripture, science, and reason. That word "universe" can be ambiguous. Scientists talk about "the universe" presumably referring to all that exists, whereas the Greeks called it KOSMOS or wrote about TA PANTA.
According to what we read in scripture, the universe had a beginning. God creates "all things" in heaven and on earth, the things visible and the things invisible (Colossians 1:15-17; Rev 4:10-11). See Acts 17:24ff.
God is transcendent which is to say, he is prior to and above, or other than, the universe which he made. God is spirit or the spirit (John 4:24). Many writers have professed that Almighty God is incorporeal. While that's not the position taken by Jehovah's Witnesses, we do believe that Jehovah existed before he made the universe. Witnesses also speak of the "material universe" (not that we're alone in this respect) to distinguish the world of space-time and matter from God's transcendent dwelling in the heavens.
How could the creator of heaven and earth, and all therein, himself be part of the universe?
God is infinite, which can mean that the deity is not limited by space or time: he is boundless in that sense. Scotus also views infinity as qualitative when applied to God (i.e., intensive), whereas Aquinas places emphasis on its "negative" feature.