Every creature and character has a listed speed, which is how far they can move on their turn. The standard is 30 feet, but some characters are a little slower (dwarves, halflings) and others are a little faster (wood elves). Once you reached the maximum distance indicated by your speed, you're done moving for that round.
Interact with the environment
Your movement also includes minor things you do to make use of what you're carrying, what's nearby, and so on. This doesn't affect your movement speed or how far you can move, though in a single move you are generally limited to one or two such interactions.
Some examples of what you can include freely with movement:
– draw or sheathe a sword
– open or close a door
– withdraw a potion from your backpack
– pick up a dropped axe
– take a bauble from a table
– remove a ring from your finger
– stuff some food into your mouth
– plant a banner in the ground
– fish a few coins from your belt pouch
– drink all the ale in a flagon
– throw a lever or a switch
– pull a torch from a sconce
– take a book from a shelf you can reach
– extinguish a small flame
– don a mask
– pull the hood of your cloak up and over your head
– put your ear to a door
– kick a small stone
– turn a key in a lock
– tap the floor with a 10-foot pole
– hand an item to another character
If you've been knocked down or are otherwise down on the ground, you can stand up by using an amount of movement equal to half of your speed to do so. Once you're up, you can use the remainder of your speed to move as normal.
You can drop to the ground for free, spending none of your movement to do so. If you are prone, your only movement options are to crawl or stand up. While you are prone, you have disadvantage for any attacks you make, but enemies more than 5 feet away also have disadvantage to attack you. Enemies within 5 feet, however, can hit you more easily than normal while you are prone, and thus get advantage on attacks against you.
When you move while prone, you are crawling and each foot you move costs one extra foot from your speed. For example, if you crawled 10 feet, this would require 20 feet of your movement.
Sometimes the environment interferes with your usual speed: snow, mud, thick jungle, sharp rocks and so on. When you are moving through difficult terrain, each foot you move through it requires an extra foot of movement. Crossing over 10 feet of mud would require 20 feet of movement. (Note that this does add to the extra movement penalty of crawling: crawling through 10 feet of mud would require 30 feet of movement in total.)
You can move through any friendly creature’s space. In contrast, you can move through a hostile creature’s space only if the creature is at least two sizes larger or smaller than you. Remember that another creature’s space is difficult terrain for you. Whether a creature is a friend or an enemy, you can’t willingly end your move in its space. If you leave a hostile creature’s reach during your move, you provoke an opportunity attack.
A creature can squeeze through a space that is large enough for a creature one size smaller than it. Thus, a Large creature can squeeze through a passage that’s only 5 feet wide. While squeezing through a space, a creature must spend 1 extra foot for every foot it moves there, and it has disadvantage on attack rolls and Dexterity saving throws. Attack rolls against the creature have advantage while it’s in the smaller space.
Journeying a great distance uses its own system of movement, based on the walking speed of the characters and creatures involved and how many hours they travel. There are three options of pace when traveling on foot: fast, normal, and slow. With a fast pace, more distance is covered but the travelers are less perceptive. A normal pace is average, no bonuses or penalties to anything. A slow pace does not cover as much ground, but allows the characters to have the benefit of stealth while they move. The usual travel day includes 8 hours of journeying, though characters can exceed this with a forced march.