Between the conversations and the fights is everything else: crossing country, searching a room, climbing a wall, running out of water. Exploration is played at whatever scale suits it — a week of travel can pass in one sentence, and a single corridor can take twenty minutes of table time.
Three levels of light, and they matter because they change what a creature can do rather than how the room looks.
Special senses cut through that unevenly, which is why two creatures standing in one room are often not in the same situation at all. Darkvision shifts each level up one within its range and drains the colour out of what it shows you. Blindsight does not use sight at all, so darkness and the Invisible condition are both irrelevant to it. Tremorsense finds only what is touching the same surface you are, and never anything in the air. Truesight sees through darkness, invisibility and illusion together.
Most of what your character spots is never rolled for. Passive Perception is a standing score — 10 plus your Perception check bonus, plus or minus 5 if you have Advantage or Disadvantage on such checks — which the DM compares against whatever is there to be found. You do not ask for it and you cannot fail it. It is simply how alert you are while not paying attention.
Going looking on purpose is the Search action, and it is always a Wisdom check — Perception for a concealed creature or object, Survival for tracks. Working out what something means is a different action: Study is the Intelligence check, and Investigation is the skill it uses for traps, ciphers and gadgetry.
Going the other way, the Hide action needs you Heavily Obscured or behind heavy cover and out of every enemy's line of sight, and then it is a DC 15 Stealth check. Succeed and you have the Invisible condition while hidden — and your total becomes the DC anyone else must beat with a Perception check to find you.
Your Speed is a budget of feet, and some ground spends it faster. Every foot of Difficult Terrain costs an extra foot — and it does not stack, so a space either is difficult or it is not, however many reasons it has to be. Climbing, swimming and crawling each cost that same extra foot, and the first two stop costing it if you have a matching Climb Speed or Swim Speed and use it. Fly Speed and Burrow Speed do the same for their own element.
Jumping comes off Strength rather than a roll. A Long Jump clears a number of feet equal to your Strength score, and a High Jump gets you 3 feet plus your Strength modifier — both after at least a 10-foot run-up, both halved from standing, and both spending movement for every foot travelled.
What you can haul is Carrying Capacity, which is a Strength question too.
A hazard is the environment doing the damage instead of a creature. There are five. Falling is 1d6 Bludgeoning per 10 feet and leaves you Prone; Burning is 1d4 Fire at the start of each of your turns until it is put out.
The other three pay out in Exhaustion rather than damage. Suffocation works on combat's clock, not the day's: once you are out of breath it hands out a level at the end of each of your turns. Dehydration and Malnutrition are the slow ones, and they are what turns a badly planned journey into a real problem: Dehydration at the end of a day with too little water, Malnutrition at the end of one with too little food.
Travel is measured in the rests it takes. A Short Rest is an hour of doing nothing more strenuous than eating, talking or keeping watch, and you need at least 1 hit point to start one. A Long Rest is at least eight hours, at least six of them asleep, and you cannot begin another until sixteen hours after finishing the last. What each one gives back is on Damage and Healing.