Below is a list of commands, that every player has access to.
/menu – Displays a GUI with all the commands
/pvp – Enable / Disable PVP
/afk – Toggle AFK status
/district – Choose a district
/ping – Show players ping
/coordshud – Adds XYZ coords and 24hr clock to your actionbar
/nethercoords – View Nether coords
/overworldcoords – View Overworld coords
/votepoints – View Vote Points
/voteshop – View Vote Shop
/trash – Dispose of unwanted items
/seen – View when a player was last seen
/solve – Solves complex equations
/recipe – Check item recipe
/playtime – View players total play time
/playtimetop – Shows top list of player total playtime
[item] – Shows item you are holding in your hand in chat
/msg – Sends private message to player
/reply – Reply to last private message
/party – Create a private group chat for you and your friends
/partychat or /pc – Talk in your group
/party shareitem – Share item in your hand with your group
/guide – Receive link in chat for website Guide
/rules – Receive link in chat for server Rules
/map – Receive link in chat for server Map