Encrypt and password protect excel file on MacBook

I am using Excel version 16.44 on a MacBookPro running Catalina 10.15.7. and want to encrypt and password protect one particular file that contains all my sensitive and personal information and data for the benefit of my children in the event of my death, hopefully not in the near future. I consulted Excel help, which told me to Select File > Info; Select Protect Workbook; Choose Encrypt with Password. However, when I selected File, I found that there is no Info option but there is a Password option. Choosing that gives the options to set a Password to open or set a Password to modify with a check box labelled Read-only recommended. 

If I just set a password to open does that do the same as the Encrypt with Password option described in Excel help and encrypt the file as well? If not, can the file be separately encrypted? If a Hacker gets past the Password protection and opens the file will s/he be able to read a file that has also been encrypted?