It's too big a topic to cover in one post, but I'd say your preferences might be more gritty than core A5E. Supply (food, water, firewood, minor medicinals, other consumables) are abstracted into a single 'Supply' value which gets depleted by exploration challenges. Taking a long rest without Supply causes fatigue (exhaustion is split into fatigue and strife) and fatigue can only be recovered at a Haven (i.e. not a campsite or a dungeon). Many food/water creating spells are altered so that they don't grant Supply. Light isn't really something A5E changes. Encubrance, well the rules are there just like in O5E; it's up to you whether you use them!
But I don’t want to mislead you—A5E isn't an OSR game. If that's your preferred style of play, I suspect an OSR game would cater more to your taste?