Never feed outside the enclosure, it can stress the animal and you do not want to move an animal in feeding mode trust me.
Live if live, F/T if F/T yes. If fe live you want to continue for 3 to 5 feeding before switching.
And yes you probably bought too much, enclosure too big so not a great starter, I will guess the thermometer are analogue (which are junk), but it's not unusual, sometimes you just need to forget everything you think you know especially when buying an hatchling.