PHP Code guideline for Codeigniter

Hello Authors

Hope you guys doing well. I’ve some question regarding PHP script code guideline for CodeIgniter.

Can i use on view file direct php echo if i want to something show on view or i need to filter those values before use echo? . If i can’t use directly echo please tell me which method i can use show value in view using CodeIgniter.

On form do i need to add csrf token on every forms ? and do i need to clean every values with xss clean?

One more question regarding jQuery using in php script How i can use jQuery. what is codecanyon requirements for jQuery .