Frequent Visitor

Hello Everyone,

        My profile says I am an occasional visitor.. Sorry guys.. I have done a few migrations from SBS 2011 to SBS 2016.

However, I am about to do a SBS 2011 SP1 to MS Win. Standard 2016/2019. I am sure I will have to update the server to SP3? Or is this really necessary? Exchange is being used for email. Looking to move them to Office 365. Can anyone give me a good insight, best practices, and over all plan?

I am reviewing this plan. But is it a good plan for this situation? Is there a better one for my situation? Any pitfalls? Help Please. 

https://opdhsblobprod04.blob.core.windows.net/contents/a723f46d716a45aabbb518bb489c832a/cd2920c0188e...