Google Sheets Email Reminders

Hi, I need a Google Sheets + Google Apps Script based reminder system for my travel agency. Requirements: Google Sheet to manage airline group PNRs. Fields: PNR, Airline, Sector, Seats, Payment TL, Name List TL, Status, Remarks... (Budget: ₹1500 - ₹12500 INR, Jobs: Automation, Data Management, Google Chrome, Google Sheets, JavaScript, PHP, Scripting, Software Architecture)