Hello Jenem. When there is no customer in your database SambaPOS will not display (select customer) button. After creating customers SambaPOS will display that button but on first customer creation you'll need to logoff, login once to refresh screens.
Customer button is grayed because you didn't created the ticket yet. After adding lines that button will enable. It might not seem logical to you because it seems you need to select / create a customer before creating a ticket. This is how delivery department works. Go to departments screen, create a new department, name it as "Delivery" and select Department Type as delivery.
After logoff-login you'll see two buttons next to keyboard button.
By clicking these buttons you can instantly switch between table selection screen and customer selection screens. On customer selection screen you can Create customers or search customers by their phone number, name or address. You can create ticket for a customer by choosing "Select Customer" button or you can display past transactions of a customer by clicking "Customer Account" button.
You can easily add the customer name to a bill by editing the printer template. While editing the printer template you'll see all available values that can be printed on a bill. {ACC NAME} is the tag that can be used to print customer name on a ticket. Just add this value in "Header Template".