There’s already a lot of comments but let me share my thoughts. I learned a bit of blender, then was taught max and looked at how it was on blender so I learned both at the same time.
I recomend you looking at Arrimus 3D videos, which are the best you can find on the whole internet, free or paid and he uses max.
For me switching between both is no problem when it comes to navigation, moving and rotating are swapped and if you don’t use the scroll wheel you have another different shorcut, but if you used maya navigation it would be more different, and I don’t like having to press alt for everytime you move.
Coming from blender you will find shorcuts for modeling are almost non-existent, you have to edit BOTH editable poly and edit poly modifier, there’s no faster way for that, configure one of them write them down on a piece of paper and configure the other section.
Apart from that I have a few shorcuts for adding modifiers, one for adding an edit poly modifier and another for turbosmooth (Subdivision surface equivalent), I also have another for collapsing the stack (You can right click the modifier list and collapse to editable poly if you don’t want to look where to add the shorcut or are fine without one). Collapsing the stack is good to keep Max stable and not having a crash each 10 minutes or less.
Some useful modifiers are: UVW Map, Symmetry (better than mirror modifier) and blender’s simple deform which in max is split between 4 modifiers with the same name as in blender. There’s no array modifier, but you can download this https://www.itoosoft.com/es/freeplugins/clone
Also some modeling commands are under the ribbon menu, where everything from the edit poly modifier is duplicated with icons as well.
Also is very useful to use some modifiers in the object submodes, for example adding a FFD (Blender’s lattice) while some faces are selected, allowing you to only deform a part of an object. You can use the symmetry modifier after selecting a vertex and it will mirror along that point as a “pivot”.
I would recommend you checking @polynut 's thread about switching to blender from Max, since you will probably find a lot of the “where” as the first reply mentioned.