My opinion is that this universe, or collection of matter, is nothing special at all. It's just one small object in an Infinity of such objects in Infinite space. Like anything that grows, there is a seed, it grows to maturity, it dies and decays and the matter (which decays or changes beyond our abilities to detect) is reused again and again. As for the seed, they usually come from the plant that existed before and seeing that I believe Infinity Exists that means there never was a first seed. I don't believe there was a first anything. I also don't believe there is one of anything except one Infinity.