Your spreadsheets are already all password protected, in that one must log in with their google account (and thus password) to view the spreadsheet. You can control who may access the spreadsheet by clicking on the "share" button in the upper right and editing what permissions users with access to the spreadsheet are given.
It's not possible to block a range from be edited by the owner of the spreadsheet.
Alternatives
Transfer the ownership of the file to one of your parents and let them set protection for the columns.
Use another spreadsheet owned by one of your parents make them share it with you with view access and import the column using IMPORTRANGE(). It's recommend that set a column to hold keys/ids for the records in order to prevent misplacing of the related data.
However, if the spreadsheet is used for viewing data (and not entering or modifying) you could make a new spreadsheet for each user, and use importRange from the "master" spreadsheet in each copy's "A1" cell. Each copy can then freeze/hide/filter as they please and their data will update almost in real-time as the master spreadsheet changes.
One dissadvantage is that you will lose some collaboration because making a cell comment etc will only be in each user's copy, so for adding comments or modifying you need to go to the master.
As a bonus, you can add an extra sheet on each of the copies and put a link to the master spreadsheet there so its easy to go to the master.
Best Answer
Your spreadsheets are already all password protected, in that one must log in with their google account (and thus password) to view the spreadsheet. You can control who may access the spreadsheet by clicking on the "share" button in the upper right and editing what permissions users with access to the spreadsheet are given.