The trinity is one of the “great mysteries” of the christian faith. A “great mystery” is really just another way of saying “Over the course of being invented by iron age goat herders, manipulated by the church, and then translated over and over again by scribes, this shit makes no logical sense.”
The Arians had it right. Father and son have distinct definitions. A son cannot exist before the father that begat him. A son is literally the offspring of a father. Created by that father. Existing after that father. They by definition are not the same being. Brothers would make more sense. They at least can be created at the same time as twins, neither existing before the other. But then that raises the issue of two gods plus “who was their father”
Also, where is the mother in all this? If god is the father, Jesus is the son, then who is the mother? Don’t say Mary because while you might claim that she is miraculously the son of human Jesus, Jesus existed before he was sent by god to earth.
“Well that’s simple GP, god can create anything, so he created a son without needing a woman”
First off, does the sexualization of god not bother you? Secondly, then why the hell do we have two sexes here on earth? Would it not be easier to just reproduce a-sexually? Think of all the “problems” that would be solved if humans reproduced a-sexually. No Eve, no eating from the tree of knowledge, no sex and the “sin” that goes along with it, no prostitutes, no women to subjugate, no rape!
The Godless Paladin 
Ask your Dad that same question.