I'm still very new to this, so please take this direction with a few grains of salt. but, I know people who are good at breadmaking and they gave me these directions; I've added my own small annotations based on my own experiences.
also, i think breadmaking is a bit more of an art than a really precise science (for all that it is kind of a precise science). unless you really, really mess something up e.g. something is on fire you'll probably turn out some kind of bread from these directions, but making a really nice loaf can be hard, and bakers throughout time and cultures all have their own idiosyncratic ways of making their loaves both distinct and good. if you bake your own bread you may have some way of doing things that directly contradicts my direction here (which i would love to hear btw i'm still not very good), or you may get advice or measurements that look very different. but again, you'll almost certainly turn out something that's at least edible no matter what.
the ingredients for this are just flour, water, and salt. ideally you will already have some kind of starter: if you don't, try asking someone who does for a little bit, or you can make your own using wild yeast (should be pretty easy to search for instructions on how to do that; basically you leave a jar with flour and water out for a week or so). this way of making bread is kind of like sourdough because it doesn't use instant yeast, but levain is a little different than sourdough starter – i think mostly it's lower maintenance and less sour tasting? again, i'm not an expert.
that said, i recommend using organic, unbleached white flour for this recipe, especially if you're new to it. it should have the best yeasty critter food in it or whatever (definitely a technical term).
you will need a kitchen scale.
if you've gotten starter from someone in the form of some dried up bits in the mail, you can follow this to turn that into proper gloopy stuff.
mix starter (dried) with 75 g flour and 75 g lukewarm water. put in a container that’s not very wide (rising level isn't visible) or too narrow (can't mix well). i use a wide mouth mason jar because that's what i have. mix it up. put a rubber band or piece of tape to mark the top of volume and let it sit in a sort of warm place – 75 F is ideal, not over 100 F. wait until it doubles in size. once it doubles, you’re good to go – use it for bread. doubling could take like 5 hours, but depending on the weather might take longer or shorter.
once it doubles, put it in the fridge. it can live in there pretty much in perpetuity until you're ready to bake.
feed the starter 50 g flour and 50 g warm (but not hot) water. let sit (proof) until doubled and quite bubbly, using a rubber band or piece of tape to mark the level so you can see it rising. will take several hours at minimum
mix (first starter and water, then flour, and salt on top):
fold the dough on itself so it coheres a bit and isn't just a lumpy mixed up mess
get your hands real wet and do a coil fold (you will definitely need to search for videos of this if you haven't done it before).
i am very bad at this part so this might not be the best advice you'll get, but the goal here is to have the ball of dough feel heavy and glossy and smooth and tight, a "happy baby". don't overwork it. if it's not at this point after a coil fold, wait another 20-60 min and repeat. if it's not at that point after another coil fold, repeat again,etc.
once you're satisfied with your coil folds, put the dough in a fresh container without any shaggy dry doughy bits stuck to the side. put it aside to proof, marking the container so you can see if it doubles.
put the dough on a floured counter. laminate the dough: stretch it into a rectangle and fold all the corners in to make a tidy little ball (there are videos of this online, too). leave it out on the counter uncovered (it's okay if it gets a little dry).
okay, that's what you hope happens. what happens to me typically is that my dough is just like, gloopy and the texture of oobleck because i'm not very good at my coil folds yet. if this happens, do your best to just continue anyway – you won't be able to do the shaping or anything properly and don't worry about leaving it in a ball shape on the counter in the next step (you can just put it directly into a bowl). it won't have incredible oven spring or anything probably but it'll still be good, edible bread.
turn it over and laminate it again. it will feel tense. roll it in rice flour, sesame seeds, oats, semolina, or something else similar and put it tense-side-down, seam-side-up in one of those fancy bread baskets things or just like a bowl or whatever. put it in the fridge.
i use a dutch oven for my bread, which i highly recommend (they're pretty cheap off ebay). i'm sure you can do this just in a normal oven but my instructions here will be for baking in a dutch oven.
heat your oven with the empty dutch oven in it to 475 F. turn your bread out tense, seeded side up and slash across the top (this is harder than it sounds, and having the proper tool for it will make your bread significantly better. i don't have one yet). bake covered for around 20 minutes, then uncover and bake for another 20 (the crust can go pretty dark, so don't be scared if it looks brown).
my apartment gets pretty cold in the winter so i have a hard time getting anything to rise in a timely way just by leaving it out. if your oven has a proofing setting, use that. if it doesn't but it does have a light, put your dough in the closed, off oven with the light on. if your oven doesn't have the proofing setting or a light (like mine), put a couple of containers of boiling water in the closed, off oven with your dough, replacing with new hot water as it cools. it creates a warm, humid environment that's good for proofing even if your home otherwise is cold and dry. you can also try taking a very hot bath with the fan off and leave your dough on the bathroom counter, but i can't actually recommend this for like, bathroom sanitation reasons.
fortunately i haven't yet had the experience of baking bread in over 100 F weather conditions, so i have no tips for that and frankly i hope i never will. that sounds miserable
good luck!