Your first move is a guess, if you hit a mine oh well try again. After that the numbers in each square tell you how many mines are in the 8 squares around that square (up, left, down, right, and diagonals). Using some logic you can eventually deduce where mines definitely are and mark them (right click) so you don't accidentally set them off. Using further logic you can deduce where mines definitely aren't and then clear that square. That's really it. I'll leave figuring out the logic as an exercise for the reader.
honestly its quite simple, each square has a number, that number will tell you how many mines there are next to it, so if it has a 1 there is 1 mine but if it has a 2 there are 2 mines, the aim is to use the information from each uncovered square to find out where the mines are and avoid them, i do wish minesweeper had a tutorial though
https://youtu.be/5mLX7S-1TiI
It's like not u don't remember but u really don't know how to play it properly.