I'm not familiar with the WIFI only option but I would have guessed if its the WIFI only option you will only have a micro SD memory card slot available..... not a sim slot. the 4G / LTE model would have a sim slot... these would also be higher in price in comparison to the WIFI only stock.
normally to use Internet on the move you can hotspot wifi off your phone OR buy a mobile WiFi device (MIFI)... a portable little box which you put the sim in and it acts as a portable router.
oh right , i not bothered about the sim card for call and that , i keeping the tablet of sky for that , this new tablet would be ok for me , as i am house bound most of the time disabilities , so will need to learn with it thanks
yeah you bought the right one... WIFI only will do for you if its going to be mainly used at home. you won't need to buy anything else more. always be wary of sales people trying to sell you stuff you don't need when it comes to gadgets.