1. Without PlayerTemplate:
Open the new Interface Function SP8_CanCreateGuild inside the Player BP
With PlayerTemplate:
Overwrite the Function SP8_Overwrite_CanCreateGuild inside your Player BP.
Set the returning Value of the Function to true.

Of course you can put your own Logic in there, for example if the Player needs a certain Level or if you want to use a NPC for creating a Guild.
And you should check inside this Function, if the Name of the Guild is a valid Name.
For example if the Name is not to big or to small.
2. Go to the Details panel of the SP8_GuildComponent of the Player BP and set Default Role Names to the Roles you want.
I will go with Leader, CoLeader and Member, so 3 Roles.

Now you are able to call CreateGuild on the Guild Component.
Look into SP8_WBP_Guild inside the Directory RPG_Essentials / Example / Widgets to see how the Guild Widget could be made.