To sprint in Minecraft Java Edition, you need to press and hold the "Shift" key on your keyboard while moving. This will cause your character to run at a faster speed, allowing you to cover longer distances more quickly.
To stop sprinting, you can release the "Shift" key or stop moving.
Note that sprinting consumes hunger points more quickly than walking, so you will need to ensure that you have enough food in your inventory to sustain your sprinting for an extended period of time. You can replenish your hunger points by eating food items, such as cooked meat or apples.
You can also enable the "Sprint Key" option in the game's control settings to allow sprinting by pressing a different key or button. This option is useful if you prefer a different control scheme or if you are using a controller instead of a keyboard and mouse.
Additionally, you can use various items and enchantments to boost your sprinting speed or reduce the hunger cost of sprinting. For example, the "Elytra" wings allow you to glide and move faster, while the "Swiftness" potion increases your movement speed. You can also use the "Feather Falling" enchantment on your boots to reduce the hunger cost of sprinting, or the "Efficiency" enchantment on your tools to mine blocks faster while sprinting.