I do the occasional cider, at its simplest I stick 5 litres of apple juice in a demijohn (with an airlock) and 1/2 teaspoon champagne yeast, 1 teaspoon yeast nutrient leave for 2 - 3 weeks then bottle and leave for another month or two and it’s real tasty.
Variations include brew a couple of bags of earl grey for extra flavour. Maybe 200g sugar if you’re feeling adventurous - go for a bottle of ribena for a blackberry cider. Just make it up to 5l with apple juice. My last was brilliant but 8% so not an everyday session drink!
I’ve just experimented using nothing but cherries and berries squash, sugar, water, yeast + nutrient. Only a month old but a bit like drinking 4% neat squash (used 1 litre squash likely too much) - if I can get that sweetness right, I’m producing my own kroppaberg!