Please note that there will be times when you won't find an exact location for a specific number. We started with the number 1, so our next number will be 2, then 3, 4, 5, until we reach 9. Once you go through all possible regions this number might appear, move up chronologically to the next number and go through the whole process you did for the first number. Now go and look for another region this number is missing and try to see if you can find the exact location this number has to appear and so on.
When you find an empty cell where this number has to appear, write it down. Then, according to the rules, try to see if you can conclude where it has to appear over that region. Start with the number 1 and search for regions it is missing. The easiest way to solve a Sudoku puzzle is to work systematically. You will have to fill the rest of the puzzle using those clues and according to the rules. When you start to solve a Sudoku puzzle, a part of it is already filled with numbers.