Question : Can we edit the php files of the joomla?

Hi there;

I am a pretty newbie in joomla. I have PHP, HTML and javascript/jquery knowledge. My question is:
Can we edit the php files of the joomla? I mean are they to be preserved in the first place? Of course, I edit configuration.php but I am asking this for other php files.

Moreover, again from admin panel, I am aware I can edit html code, but am I allowed to add javascript code and/or php code from the admin panel directly inside of html code view?

Best regards.

Answer : Can we edit the php files of the joomla?

yes may be.

I suggest you to try for searching the extension available on net which complete all your requirements or some part of your requirements.
And start to edit that extension to make it as your requirements.

Hope this helps
Addy