Ask HN: Provide me ideas to code up for a school task that I have to do

I have to code up an app for a school project following this project description: Find problem to solve that client has or propose to create a product that you believe will be useful to others. Solution must: • Security - more than one user, pages and site locked unless logged in • Validation - existence, type, range • Complex Code (User defined Linear Search/Binary Search and QuickSort/Selection Sort) • Data entry • Data Deletion • Data Editing • Data Storage - more than one data file • Data Retrieval • Data Searching • Data Sorting • Object Oriented Programming Feature Think - What data do I need to collect to work out the requirements of the solution