How would you attach an interior wooden wall to a metal building?
I would not choose the path in your first photo unless you verified with the company that engineered the steel building that the additional dead load from the wood framing, drywall and what ever you might use the wall to support is adequate.  I would think it was not engineered for the load and could cause problems later.  

So, second photo, the wall dead load is supported by the floor.  Hopefully the slab is not really thin and poorly reinforced.  In that photo from the height of the building, I am guessing the floor was reinforced poured with the intent for light-industrial taking place in there.   If you are doing free standing walls, avoid powder actuated fasteners, they have very poor pull-out resistance.  Use a wedge anchor or a sleeve anchor.  

To fasten the walls to the steel posts of the metal building use a #3 point, washer hex head, self-drilling screws. You can find them at Fastenal.  Space them 1-1/4" from the stud edges and in an alternating pattern every 15"-18".  I personally also like to use extra-thick fender washers, sometimes called heavy washers to increase the pull-through resistance.  A premium poly-urethane construction adhesive would increase the holding power considerably.  

I would insulate the steel wall first with rigid foam insulation panels to fill the depth.  I would then use fiberglass batt in the studs. If this is commercial or industrial, your electrical might be required to be in conduit or MC cable, Codes are not the same everywhere. MC can be run though holes board in the studs similar to NM cable.