You can use 12, but 10 might not be a bad idea on runs of that length because of voltage drop issues. You only need 12G for the ground, even if you size up the current carrying conductors.

Most likely it's going to be a WET location, you need wet rated conductors. You need to use conduit that is approved for sunlight exposure if you want to use plastic. If you want to use rigid or EMT you must have it approved for wet locations (corrosion resistance). The conduit can be used for both purposes you suggest. You can get away probably with appropriate rated (wet and sunlight approved) cable like some UF as well as long as you can follow a surface and there's no problem with physical damage.

You need GFCI protection for the receptacles. The light only needs GFCI protection if the manufacturer's guidance requires it, though you're free to do so optionally.

Is there a type or a rated EMT for wet locations? I know I can get wet rated wire, and wet rated receptacle, what else?

EMT or Rigid itself doesn't need to be wet rated, but the associated hangars and other hardware need to be corrosion resistant when used in wet locations.