I'm not familiar with that particular brand, but it looks like a well-equipped package for the money. 1500 watts should be more than plenty to light a family-sized group.
It's a pretty big topic to cover - how to pose a family, I mean. When you start out, I think you may benefit from hitting the books a little. Most libraries should have a few books on the subject.
Generally there are two schools of thought - one favors a very directive approach where each individual is posed just so. The best ones in that business have the advantage of getting families, who aren't naturally adept at this in front of camera, to appear very intimate and comfortable.
The other school of thought is to just "let loose" and see what happens. A more candid approach where you set your gear up in their homes and have them either play a game around a table, bounce a balloon back and forth or play a word-game, tell jokes, whatever...and then you catch them with shots when something fun and natural happens. This approach has the benefit of everyone KNOWING that nothing is faked..there is no pretense..it's really real! But, it takes a lot longer and may not yield the "pretty" and "formal" shots that some families want.
I think you have taken on a big challenge here, if you are starting out in portraiture with a full studio-set-up and shooting entire families as a start..lol. Understanding light-ratios, flash-synchs, how light falls best on a face and a body of ONE individual is tough enough. Getting all this to work together for a whole family...can be very tough.
Families where the kids are young teen-agers with bad skin, self-conscious and in the "rebel against the parents"-phase..well you can imagine...they don't want to smile because they have bracers..in fact they don't even want their pictures taken, but mom&dad insisted..
My intent is not at all to discourage you, but I do recommend getting a great deal of practice before you have customers pin their hopes of memorable family moments on your abilities to overcome perfectly common family dysfunction..lol. On the other hand, if you can get younger families with young children...the kind that just want to crawl all over a big couch, their parents and swing stuffed animals around...then you are OK..you can instead focus on the thrill of getting the light-ratios to work..lol.
From the perspective of posing, I suggest you OBSERVE, OBSERVE and then OBSERVE some more. You need to have a menu of possible set-ups and poses in your head that you can draw on and try out. Kids between parents, kids ON their parents, Dad with his head in Mom's lap and a toddler sitting on his tummy? Smaller kids may react favorably to props..something that makes a sound, so you can get them to look towards the camera..or at least not have their backs to you..
...ahh so much to cover..lol..I wish you the best of luck. If this set works as advertised, you have "no excuse" not to get suitable lighting on the subjects.
Hope to see some shots from your practice!