Managing tables in database

I am new to web development field and particularly very poor at database management. I am developing a web application which resembles Project Management System where new companies can add their profile, create a project under them, under each project they can create a new task and so on.... Hence, my question is right now is should i use one common table for all the new profile (abc & co) created and one common table for all the users registered under profile (abc & co) created, or should i create new tables for each when a new profile is created and new table for each users and project created ?