What is that?
Right now, I have my brewing bucket that I put my wort into and once cooled, pitched the yeast and waited? Is that the primary fermenter?
If so, what is the secondary fermenter, and is that step something you can skip if you want to?
yes, the bucket is your primary and you "could" bypass a secondary if you want to. However most all will recommend that you get a secondary as well. A secondary is typically a 5 gal glass carboy. Your beer will be better if you do the two-stage fermentation in clarity and taste. The typical process is as follows:
3-5 days in primary then rack (transfer to secondary)
approx 14 days to settle out in secondary then bottle.
approx 14 days in bottles to condition then Drink!
rules can change based on the beer you're brewing but this is the 'typical process'. Do a little reading as to optimium times to transfer (rack) & sanitation is your friend.
Oh, and if you do bypass a secondary you must keep your beer in the primary for much longer than 3-5 days. How long would probably be 14-17 days in total. But once you open it up you'll notice all of the gunk in there and the objective of the secondary is to get it off this byproduct of the initial fermentation which can create off flavors.