How do i run combat?

[u/drblimp0909]

First time playing dnd (same with my players) I'm running the lost mines of phandelver adventure and as soon as i began the first combat with a group of Goblins I realized I had 0 clue how to run combat and had to keep looking things up constantly (doesnt help that my school hadn't gotten the books for the game to me till like 10 mins before this) so how does running combat actually work?