what maxi-model writes.
but as you declare to be new to all this, i would like to add some things.
being in the states, beware, if you buy from europe. you need a transformer/regulator with input of 110volt. european transformers have an input of 220volt.
if buying an LGB transformer/regulator from amazon or ebay, look at the pic. the red LGB ones are european, the grey ones are US type with 110V input.
for a LGB loco you need a transformer/regulator with DC current output. (more than 12, better 18 or up to 24volt, no more) (on LGB regulators the red and the blue output terminals)
you best look for transformer/regulators in one unit. (recognizeable by the dial upon it.)
but first things first...
do you know, if the loco still works?
take a battery (good would be one of these little rectangular 9 volt batteries) and a piece of wire.
when you touch the poles of the batterie to a wheel on different sides of the loco, the wheels should turn. turn the batterie around, the wheels should turn in the other direction.
if the loco doesn't work, get it fixed before you spend money on a transformer.
good luck, and welcome.