Bokashi composting is designed for use indoors, usually, in relatively small containers with a lid. The bran that you need is inoculated to activate the fermentation process - more information in the link below
You've said you don't know what to do with what you've got now. I don't know what to tell you, really - bokashi is normally used indoors, and does need to be 'finished' by adding it to a compost heap outdoors or placed in the ground to deacidify.
The principles of other composting are these - the heap must be no smaller than one metre cubed, and for preference, should be turned weekly. It's best not to add citrus peels or leaves, the main components being garden waste and perhaps peelings from different vegetables, banana skins, eggshells, that sort of thing. Clearly, that's not an option for you, and bokashi would not seem to be suitable either. The only other option I can think of is vermicomposting - but you have to be brave about having worms in a bin in your house. Information in the link below
but there's plenty of info on the web about it. However, given you have no garden or space outdoors, I rather wonder what you will be doing with the resulting compost...
You can get a 50 litre bin (though I'm not sure what the height, width and depth of that would be) and you can put your stuff in it, but it'll have worms, bacteria and pathogens in anyway, if you add soil - even without soil, you'd need to inoculate with something to get the composting process going, whether that's soil or worms or bokashi bran or compost activator products. Composting is only the activity of bacteria, fungi, worms, other organisms consuming and excreting the waste, and in the case of bokashi, yeasts and moulds as well. Other than Bokashi or vermicomposting, composting often may attract undesirable insects within the home (flies). Composting down that amount of waste in a home environment isn't something I'd recommend, frankly, not to mention, you'd need to turn it twice a week to create heat, and probably again to dissipate heat so it doesn't get too hot. Without this heat, you cannot use the resulting compost for potted plants, because the heat is what kills any pathogens present.
More technical info regarding temperatures of composting processes in the link below