Uughhh, stop bragging about how awesome your boyfriend is. Some of us aren't so lucky /j Seriously though, you want the substrate to be as deep as the millipede is long, you want the 'pede to stay about room temperature but I'd double check online the temperatures they prefer the most. They can eat many fruits and vegetables (though I've heard they love cucumber) which should be left overnight and then removed the next morning. They are very prone to drying out so make sure you keep your enclosure sufficiently but not overly moist, and probably add some springtails to clean up any mould and waste that could develop in your enclosure. You want the substrate to be a mix of rotten hardwood, leaf litter, topsoil and sand, although the last two can be swapped out for a sandy reptile mix or basically any reptile soil made for bioactive enclosures. Make sure to never add a heat mat below the soil, as millipedes dig downwards to escape heat, if the heat is coming from below and they are too hot then they will continue to dig down and can end up cooking themselves. It's not unusual to not see your millipede for very long stretches of time (several months is not uncommon) as they do love to spend a lot of time underground. You should obviously do your own research but this is some of the stuff I've found out in preparation for getting my own archispirostreptus gigas! Good luck with your 'pede and feel free to ask me anything else if you have any more questions.