I could give a brief precis of what the current thinking is in cosmology.
Most of these concepts are difficult.
Please watch these videos. You will be at best disturbed and at worst a bit frightened.
https://www.youtube.com/watch?v=V9MVVPmApt4
https://www.youtube.com/watch?v=NsbZT9bJ1s4
https://www.youtube.com/watch?v=Z_KI9sjyVIQ
Bert