well to make a symbol bigger or small , right click it and select scale or rotate, and select the small squares or circles that surround the object to modify its shape accordingly, to make sound you just make a new layer, and select a frame, and go to file>import and find the sound file, it will import the sound onto your timeline just like all the drawing and stuff you have, you can select the first frame of the sound and move it to where you want it to begin.
AS for animating, you can either draw the guy frame by e frame, which can be tedious but gratifying once its done (sketchbook series, i like to beat things), or you can draw each joint of a character seperately and convert them to symbols and move them frame by frame, best used in sideview of the character(brutality) good luck, those are alli can answer at the moment without making the post seem like one big mass of words...