Did God create this universe or was it a happenstance?

[Zmouth]

How did this universe appear?

Not that any man hath seen the Father, save he which is of God, he hath seen the Father. John 6:46

It is kinda like lyrics of the Eagles song, Already Gone;

For as the Father hath life in himself; so hath he given to the Son to have life in himself; John 5:26

"... the Lamb slain from the foundation of the world." Rev 13:8 But you already know that which is eternal can neither be created nor destroyed, so in the beginning signifies point at which the Son was given to have life in himself. And of course where do you live?

Who is the image of the invisible God, the firstborn of every creature: Col 1:15

1 Tim 6:16 * John 11:9-10 * 1 John 1:5-6

 

[Tintin]

in the beginning, there was nothing. then God created light. and he saw that it was good. on the second day he created the heavens and the earth, and he saw that it was good.

Not quite. In the beginning, there was nothing by God. He created time (in the beginning) and space and matter (the heavens and the earth = the universe). But the universe didn't yet have form, nor was it yet inhabited.

 

[Tintin]

My theory

God spoke .... it caused a bang .... God controlled the events of the bang to make the universe ,,, the he specifically created earth and so on

And what informed you to believe this? Certainly, not the Bible itself.