I am creating an app which is described here:

This program helps make planning and transportation from Jackson-Reed to the boathouse more simple and organized. It will create a space for teammates to reserve seats in cars driving to the boathouse, reserve space in cars for their stuff to be transported to the boathouse. It also provides a space for drivers to sign up to drive, make storage space and seats available for teammates to claim and allows drivers to mark pick-up locations and departure times.

My Solutions Overview is :

HTML CSS My SQL

File structure so that there are folders for CSS images classes and includes

Config?

Re-use as much code as possible

Design CSS for the whole app not just one page at a time

Shared header and footer

Ensure that SQL is secure

Add in error checking and data validation for all user input including testing edge cases

User object with username, password, how many seats and storage space the users car has

layout should adapt to fit any device (make sure functional on phones especially)

More than one user table?