Base info about distilling.
Distilling all it does is strip the alcohol out of a low % wash/beer/wine whatever and condense it to a higher %. The process is done through evaporation and condensing. Ethanol "alcohol" has a lower boiling point "78C or 173F" than water "100C or 212F" so in the process one will boil off the alcohol before the water will have a chance to change to a vapor aka"steam". Then we just condense that vapor back into a liquid through cooling getting a condensed higher proof end product.
Still types, you more or less have two types. Potstill styles are where all vapor produced is pushed over to your condenser and made back into liquid, they are great for flavored alcohols, rums, whiskeys, brandys, anything where you want the flavor of your wash "starting batch" to transfer over into your final product. The other type is reflux/fractional stills where you condense your vapor and send some of that condensed liquid back down your column to be reheated to become vapor again. That causes the vapor to stratify and separate out so you will only have pure alcohol vapor at the top of your column. The advantage of this is you can make really high proof alcohol in a single run if desired. Where as a pot still will take many runs and some flavor does come over to get almost the same high %. So they are awesome for neutral spirits such as vodka, and or neutral spirit bases where your adding flavor afterwards such as liqueurs.
Reflux columns are usually the best starting point as apart from doing high proof neutral spirits they can also be run in a potstill style operation where you off take all the vapor you condense. Pot stills have to run it multiple times to get high proof stuff 80+%, but they are great for the flavored stuff.
Alcohol which is Ethanol can only be distilled up to 95.6% as it creates a covalent bond with water. You can further chemically dry or use molecular sieves to make it 100% but it will literally put water out of the air to bring it back down to 95.6%.
Your starting wash can be made from literately anything that has a starch or fermentable sugar that yeast can feed on which in turn produce alcohol and carbon dioxide, plus a whole bunch of minor things. Myself i typically make rum batches literally composed of Water, sugar, molasses, and yeast. The molasses typically provided enough nutrients for the yeast to have no issue, its no different than out plants. But you can literally make washes out of just water sugar and yeast so long as you have enough.
Fermentation typically takes a week to two with a bit of time to have the yeast settle out, then your ready to run a batch.
My average cost for my rum washes work out to be around $1.30 a bottle "750ml or 26oz" at 40-45% alcohol content, electricity cost included.
Oh and proof for those in the three counties in the world that don't use SI units or still use it as measurement is an older type measurement system where you literally mixed alcohol with gun powder which would be lit to see if the gunpowder would go off, if it did it was "proof" that it was high alcohol content. But Proof is actually just double what the percentage is for 80proof = 40% Alcohol by volume.