Developing 2 Simple Php scripts & Invoices Manager

I have 2 PHP scripts running on Linux servers . One of them is Renewal script & the Other for Addon Features . The Two scripts is already done & working . What i need the follwoing 1-To add some New Features to the Addon working with Calculator . 2-Few modifications (Adding Username of client , His domain ,Password , etc.) to the the Renewal form . 3-To send Notification Email to Customers Before Renewal with X days that i can manage so it will Need CREATING DATABASE to save all my Customers (Prefer MySQL) to send Invoices before X days of renewal . ## Deliverables What i need the follwoing 1-To add some New Features to the Addon working with Calculator already existing . 2-Few modifications (Adding Username of client , His domain ,Password , etc.) to the the Renewal form . 3-(Invoice Manager)To send Notification Email to Customers Before Renewal with X days that i can manage so it will Need CREATING DATABASE to save all my Customers (Prefer MySQL) to send Invoices before X days of renewal . ## Platform Linux Server