In the sidebar, with your club selected, click "Members".
If you don't see this in the sidebar, it might be because you're not a manager for this organization.
Find all the information you need on how to be a manager of an organization on the "Manage your Managers" chapter.

Check that you are in the "Members" tab at the top of the page.
If your club already has members, this is where they will be displayed.

On the right side of the page, click the "+" button to add a new member.

A dialog will pop up.

Fill in the details for the member you want to add.
Fields with "*" are mandatory.

Please note that if you are creating a gymnast, you will have to fill some additional details on the "Gymnast" tab.

Once all the details are filled, click "Create" and the new member will be added to your club.

Double click the member you wish to edit.
Alternatively, you can select the member with a single click and then click the edit button on the right side of the page.

A dialog will pop up. The fields will be filled with the member's details.
Simply edit the fields you wish to change and, when you're done, click "Save".
Select the one or more members you wish to delete with a single click.
Then, on the right side of the page, click the delete button.

A confirmation dialog will pop up. Click "Ok".
Alternatively, you can delete a member by double clicking it, and clicking "Delete Member" in the opened dialog.