I'm beginner in the sudoku, can anyone explain how I solve this?

Few things I want to know about the solution are:

1) first number you solved in this and how? 2) is it possible to solve it just by 2 pencil marks? 3) is it possible to solve it without any special tricks?

Thanks in advance <3

Few things I want to know about the solution are:

1) first number you solved in this and how? 2) is it possible to solve it just by 2 pencil marks? 3) is it possible to solve it without any special tricks?

Thanks in advance <3