Can I create a new character without joining a table?
Yes, you can!
Select the system you wish to create your character for.
To do this, go to Shop, click on System and select a system from the list.
In the window that opens, click on the blue +Create New Character button.
Assign a name to your character (you can change it later) and click on the white Create my Character button.
Then create your character according to the system rules and/or your GM's guidelines.