Hello,
I have an exposed concrete front porch that's 5'x7' with 4 steps
and a landing. I was thinking of refacing it all with porcelain tile.

What type of grout should be used for this type of application?

What type of mortar/thinset should be used for this?

You should determine if the porch has enough slope for it to shed water properly. Any cracks or low spots? You're going to need some type of waterproofing on it to keep water that gets under the tile from freezing heaving the tile.