Open Minecraft and join or create a world
Press Esc and open Settings if needed
Go to Video Settings or Accessibility Settings, depending on your version
Turn on Player Names or Nametags if the option is available
Make sure Hide HUD is turned off
Make sure the player is within render distance
Make sure the player is not sneaking, if using Java Edition
Make sure the player is not too far away
Check that the server does not disable nametags with plugins or commands
If using Bedrock Edition, enable Gamertags in the world or server settings if available
If using Java Edition, press F1 only if you want the HUD visible
Restart the game if the nametags still do not appear