Hello and welcome
Aw poor thing with its tale...it may not have been eaten off though. Leo geckos drop their tale if they are threatened or very scared so it could have dropped off, if that's the case then it will grow a regenerated tale, Google it for more info as I'm not an expert but I know this tail-dropping is common
I'm relatively new to the leo gecko world too, I've had mine (Elvis) for just over a month now so if you have any questions as a newbie, just ask!
This is basically what I have in my 2ftx1ft viv = heat mat that covers half the vivs floor space, red 25 watt light bulb, repti carpet, 2 hides at each end of the viv, plastic plant, piece of wood (it has shade so kinda counts as a 3rd hide but isn't enclosed), water dish and a rock with a hole in it filled with moss.
The temps in the viv from 8am-9pm are 82 degrees at the hot end and 70 degrees in the cool end and from 9pm-8am I turn off the red lamp and the temp drops from 82 to 76 and from 70 to 66ish.
Of course I put the food in which are usually medium size locusts or small meal worms and 1-2 times a week I give him a wax worm, Elvis isn't keen on crickets though.
I change the water every other day and drizzle water on the moss every 2-3 days.
Let me know if you want to know anything else

________