checkbox value for Edit not showing as checkbox checked

For select or tags, you can use this lib Select 2, it can populate data directly from the server using an ajax request. 
For multiple file handling, you can follow this tutorial - multiple file handling
To import data from CSV to the database follow this tutorial - CSV to DB

thank you @SubrataJ for your concerns to help us. appreciate your inputs and links.  
kind regards

Newbie here in CodeIgniter World !! Please appologize if any nonsense from me.  

environment: Windows 10, XAMPP 3.3.0, VS Code, SQLyog Community Ed.