If you want to create a new guild then go to the Guild menu og click on "create new guild"
When you create a new guild, you need to give your guild a name and decide how other players can join your newly created guild. Both the guild name and the application mode can be changed in the settings afterwards.
If you chose autojoin, then every player who applies will automatically become a member of your guild
If you chose "Via application" then the player will have to apply and the guild leadership can then chose to accept or reject the application
If you chose "Via Invitation only" then the guild will not accept applications but will only add new members by direct invitations.
Once you have created the guild, remember to go to the Guild administration window and update the information there