How would you approach this e-commerce customer segmentation + prediction project with GenAI?

I'm an MSc Computer Science/Data Analytics student working on a major ML project with an 11-day deadline, and I'd really appreciate advice from experienced data scientists on how you'd approach it. Dataset: ~541k e-commerce transactions, ~4.3k identifiable customers, with fields such as InvoiceNo, StockCode, Description, Quantity, InvoiceDate, UnitPrice, CustomerID and Country. It contains missing CustomerIDs, duplicates, returns/cancellations (negative quantities), and other data-quality issues. Project requirements: Perform EDA and customer behavior analysis Engineer customer-level features,