These are two different things sadly.
Windows (10, I should have added) Pro is the operating system that powers your machine. It is the business version but you can buy it for any computer if you want it. I need to travel with my laptop a lot, which is why I went all out, but I think you do not need it so long as you put the other protections in place as it does come at a substantial extra cost.
Office 365 Home is the software package you use for Word, Excel etc … having the professional version just gives you access to software like Publisher and Access in the package, but you can buy those separately if you need them … there is only real advantage to Office 365 Pro if you intend to have a bigger team of collaborators (I think).
You already have encrypting capacities as the article I gave earlier points out, but you have to remember to do it for the files you wish to encrypt whereas Windows 10 Pro comes with BitLocker as standard which does it automatically. But if you do not intend to move your laptop much, I would not worry, and if you do … just encrypt the folders you are interested in safeguarding.
Unfortunately, this is the greatest extend of my technological knowledge so do seek a professional’s expertise if you are worried … but I think you don’t need to be … and remember your advice to me about the SSL certificate I was in a flap about