Hi Elaine, first I would say that if you're just getting started that stand is way more than you need, for the money you can buy much more than that. Your first stop should probably be strobist.com, lots of techniques and examples there for folks just getting started. one thing to remember is that you don't necessarily need expensive gear for lighting, though many of the pros will prefer sturdier stuff that can withstand a lot of kicking around in the studio.
I found some suggestions there for some very compact, inexpensive gear. Since I use this stuff away from home more than at home, I didn't want big, clunky gear where it's not needed. Something else to consider is a
shoot-through umbrella which can work as a softbox, the main gotcha is that if used as a catchlight the ribs may show in the subject's eyes on very close shots.
Here is the one I use.
I have a few of
these compact stands(you could almost buy four for the cost of the Avenger) which are plenty for an umbrella or small softbox, and they are very compact when folded. You can add sandbags for stability if you're working in a breeze or have a boom attached. You may not need a boom right away, but
this one is inexpensive and versatile, it can hold a softbox or reflector and has a fitting so you can attach a counterweight.
You will want a way to hold your flash, some softboxes come with everything you'll need some need a swivel such as
this(if you are using a
Sony/Minolta off-camera shoe) or
this(if you just want to mount using your existing stand's 1/4-20 threads).
You can find off-camera shoes on ebay, sometimes for less.
Beyond that, more detail on what you're doing would be helpful. If you are using a FF camera you will need either an F20 flash or a cable adapter to trigger the flash, and the cables get expensive if the flash is more than a couple feet from the camera. You'll probably need a reflector, if you're doing this at home a large piece of foamcore or a nearby wall should suffice, if you're taking it on the road you might want to get a collapsible reflector.
Note that while I have posted quite a few links to mpex, I have no affiliation with them -- just a satisfied customer.
Also Gary Friedman has lots of good info on flash, for example
this explanation of Sony flash protocols. Depending on which camera you have he probably offers an e-book that will explain all of the ins and outs of how to get the most from it with or without flash. Again, no affiliation, just a satisfied customer.