From the Client List section, select Add New Client. (See image below.)
After this, you will be taken to the Add New Client page. This is where you will create and enter values for your new client. You can add things such as a Profile Photo, your client's email, their password (the personal trainer create the password for them), their phone number, their likes and dislikes, and other similar information. (See image below.)
You will then be able to see your client in your Client List. You can easily edit your client's information at any time by clicking on your client's name.