tonight im gettin a leopard gecko (not even a year old yet) for $1oo with tank and all, the guys son has lost intrest so they are selling it too me .. any advice for this newbe ?

i was told to TAKE THE SAND outta the tank as soon as i get it cuz the sand builds up in there stomachs after a while ... what should i put down ?coconut husk i was told is good ? and they need 12 hours of light .. but right away i can't get a small heat pad til i get paid in two weeks .. it comes with a heat bulb and whatnot... will be be okay to just use that til i get paid ?
what would be better for me to buy ... i tub of the mealworms .. or crickets?

how often should i feed him ? and handle him ? its 12:30pm here now im going to get him around 5pm so im hopeing to get some feed back befor ei go pick him up for i can go pick up a few things..

Tips,Advice and anything else you can tell me please