Automate Gmail & Sheets Workflows

I am a small business, but part of a Franchise System. I'm ready to hand off two related automation chores. Both jobs live entirely inside Google Workspace, so familiarity with Gmail API, Google Apps Script, and the Sheets API will be essential... (Budget: $15 - $25 USD, Jobs: API Integration, Automation, Email Marketing, Google Docs, PHP, Scripting, Software Architecture, Workflow Automation)