All logic in sudoku’s is based on the fact that each house (row, column or zone) must contain all the numbers once and therefore if it’s used once it can’t be used in that house anymore. Since the different kind of houses overlap, any 2 overlapping houses can reduce the possibilities greatly. You’ll want to find the combinations leading to only 1 possibility, so you are sure that the number you put in is correct.
It’s good to have a plan when solving sudoku’s. You can do this in more than one way, so it’s up to you what fits you best. For instance, you can start with number 1 and move through all the positions to see if you can logically place it somewhere before moving on to number 2 and so on. The other way around would be to go about it position by position and looping through the numbers in a position before moving on to the next position.
Also, try to keep track of positions that are close to solve. If you have solved one, it’s likely that you can also solve a related one with the new information.