In my own experience and in my observation of others, you do not need good gear or light gear in order to get hooked on backpacking. If you ask a dozen old-timers, who've been doing it for decades, about their first time out, the chances are very high that their story will feature getting cold, or wet, or blistered, or sore, or some combination of these miseries. Yet, they didn't stop backpacking because of these initial experiences with it.
The conclusion I draw from this observation is that it is OK to let your friends come along, equipped with cheap, poorly made, heavy and barely adequate gear. If they are the sort who are going to get hooked into this strange, but highly satisfying, recreation, then none of these will prevent them from wanting to go out a second, third or tenth time. They'll just learn from their mistakes, replace their worst gear, and persevere. Destiny is hard to avoid.
That said, they'll be lots better off if they can beg, borrow or buy a warm enough sleeping bag right off the bat and at least have some sort of blue foam pad and ground cloth to put under them, and a tarp that won't leak badly that they can set up as a shelter over them.
At a minimum their shoes should have some grippy tread and not hurt their feet. For this time of year, I recommend wool or synthetic socks, not cotton sweat socks, with some cushion to them. For warmth, emphasize layers, not some huge bulky coat, along with an outer layer that can shed some wind and something to resist rain. They'll need a fleece stocking cap. A lot of this can be had for cheap, or at a thrift store, but try to give them a clue about what to look for and what works an dwhat doesn't.
Food can be ultra-simple. At a pinch, it can be no-cook food, which will eliminate the need for a stove or a pot. Less gear that way.
If they can't borrow a pack, make sure whatever they end up buying has a good waist belt and make them bring a heavy trash bag to use as a rain-proof liner so their sleeping bag and clothes don't end up wet.
Before they set foot on a trail with you, make them show you what they are taking, so you can plug holes, or argue them out of foolish gear, like a cast iron frypan. Good luck and have fun!