What kind is it?
I have only raised SA aros(blacks and silvers) but the following advice would work for other aros too.
Good first food is freeze dried blood worms, need to feed soft foods upto 3-3.5" then can start on pellets. Should by kept without tankmates until 5-6". Even at a small size such as this they are jumpers, no hole too small, so secure that top. Keep pristine water conditions nitrates under 10ppm.
My opinion of an ideal set up is a 55g tank, barebottom, with a sponge filter. Keep tank water level 6" from the top and add some floating plants for cover. Always place food in the same spot of the tank when feeding. This is not all necessary but will increase the chance of it's survival, which are not very high.