Yes you can get free games on your 10.5 emunand you need to install fbi or bbm to your emunand then download whatever games you want then use fbi or bbm to install the games
No you don't need them they are for using the homebrew menu as you have emunand you only need the Fbi ciai installed fbi installer now do i need to put "FBI.smdh" and "FBI.3dsx" these files to the 3ds folder in my sd card ?
Edit : oops i forgot that i formatted my sd
No you don't need them they are for using the homebrew menu as you have emunand you only need the Fbi cia