Making kit beers is like making cordial.
I recommend getting
this from Coopers or BigW. Or you can go for the
Bunnings fermentor for around $20 with tap (its in the camping section near the pool section).
Just add the kit can (put it in hot water for bit to make it easy to pour) to the fermentor (big plastic thing). Just ensure that your tap is in place and turned to off.
Next, add your sugars. Adding a kilo of light malt extract would give you 21 litres of 4.5% beer.
Now add maybe a litre of hot water to melt your sugars and make everything easy to stir.
Next, add cold water to the 21 litre line (using the Bunnings fermentor requires marking this in advance).
Before pitching (adding) the yeast you want to ensure that the wort (unfermented beer) is 24° C or less (depending on the yeast). With the Coopers set this is as simple as using the thermometer you have affixed to the side of the fermentor. This is a good time to
measure the gravity (solution of sugars in your beer and record it). Once again this is something that comes with the Coopers set.
Sprinkle the yeast evenly over your wort (unfermented beer) or better yet
rehydrate it.
Now leave the fermentor in an area that is hopefully dark, not often disturbed, and with a constant temperature of around 20° (hopefully). I like closets and laundrys for this application.
After two weeks or better yet once the gravity measures the same over three days, affix the bottler (in the coopers set) to the tap on your fermentor. Add 2 carbonation drops (also in the coopers set) to each bottle, fill as full as you can without spilling, and add the cap.
Again leave the bottles for two weeks (one week will be less than OK, and three weeks will be better) and then taste.
For your next batch consider adding some hops.
For more (and better) information try
HowToBrew.com and
Coopers website.
I am not affiliated with Coopers in any way, but rather think their DIY Beer Kit is perhaps the best way to get started.