vinegar and baking soda will NOT make co2. sugar and yeast will. you can put a small amount a sugar and dry yeast on a two liter bottle shake it up. The first time you shake it, not much happens, but after a bit the yeast starts to feed on the sugar and the by-product is co2. Just shake it up a few times a day and each time a bit of c02 will be released. It wont do too much for you at all unless you do it in a small confined space. if you just do it in a room.....ehh....sugar and yeast are not free lol , but in a grow box, tent, somthing enclosed like that the co2 helps alot.
Vinegar is an acid source PH- baking soda is alkaline PH+ But baking soda (sodium bicarbonate) aslo contains SALT so you dont really wanna go there.
Epsom salt is a magnesium source, as well as a source of calcium. MJ does require a good amount of magnesium which is why it is commonly used by growers. But if it aint broke dont fix it. ONly use it if you NEED to, if you have a mag def.
Boiling your water is a waste of time and energy. Unless you are condensing and collecting the steam. then you'd have distilled water. Just let it sit out for 3 days to evap the chlorine or put an airstone in it. if you can cleanly collect rainwater and use that its ideal.