First of all, welcome to the forum. I'm glad that we've already been able to be a help to you

I would recommend avoiding sand even when your dragon is older. It's not the safest substrate and is very unsanitary. Reptile carpet is ok, but tends to start smelling very bad after just a short while. My preferences are nonadhesive shelf liner or textured ceramic tiles. Both look nice and are very easy to keep clean. Tiles will also help to keep the dragons nails down to a more managable length.
A young dragon should have all the live prey he/she wants in 15 minutes twice a day. For a healthy, well settled little one, this can be anywhere from 30 to over 100 insects each day. Crickets, silkworms, pheonix worms, and roaches all make excellent staple insects. All bugs should be smaller than the space between the dragons eyes.
We have a few awesome breeders here on the forum. One of the biggest advantages to buying from a forum breeder is that you can get to know the kind of person they are, and you see for yourself how they care for their babies. I have 2 dragons from Thewolfmantom, and they've been 2 of the sweetest and most laid back dragons I've had.