for making "emergency candles" honestly just use used regular old candlewax. Have friends and family gather and/or save used candles that they don't want and melt them down. They aren't pretty by any means, but for just emergency use, who cares. You just need to melt them down and remove the wick and metal wick holder that was at the bottom.
You can make candlemaking as simple or as complicated as you want. My wife makes candles of all types, and has molds for different styles and sizes, but also enjoys making plain hand dipped ones.
For the hand dipped, you can get by with just buying the wicking from a craft store and nothing else, Heat the wax on the stove inside a coffee can, supported by something underneath, inside a pot of boiling water. My wife uses either a canning ring or a small empty glass dish. Don't let the melted wax sit directly on the heat or it will burn.
Cut the wick a little over 2x the depth of your pot with something for weight tied at the ends. (I've used 3/8 nuts) use a clothespin or something similar at the top to keep them from touching(or just use two fingers),dip into melted wax, and hand over a horizontal stick or rack to dry between dips. Doing more than one pair at a time keeps the process going. Keep dipping and drying in rotation, watching the amount of wax in the pot, adding more and waiting for it to melt if necessary. It takes a few dips for it to even start to resemble a candle as it starts off as a wax covered string, lol, but after dipping over and over, the candle starts to form. I made a simple rack of 2x2 uprights and two dowel rods horizontally across the top. Two about an inch and a half apart keep the hot wax from touching and sticking together. Dip-let dry-dip-let dry...over and over and over.
Avoid using used candles with a heavy clear coat since some are wax, but some are a spray coat that will melt in the wax and cause it not to bind well when re-using. Larger candles that are white with a colored outer layer will work, but I prefer to shave off the colored layer since it's always a lesser grade of wax that doesn't always mix well. Using scented is ok, just keep in mind you will be combining the scents of all the ones you have used. You could end up with pine-lavender-christmas cookie-vanilla emergency candles, or something that smells like awful 70's avon perfume. (hey it may work on mosquitos lol)