Questions about Script

Good afternoon.

I have questions on making a change.
1. How to change the color black to green, in which file to change? See Princescreen.
2. How to remove unnecessary fields? See Princescreen.
3. How to add a flag for the language? See Princescreen.
4. I want to add a new word in the language file added:
$lang_user['poweredbyfooter']            = 'All rights reserved';
$lang_user['helpme']            = 'Help';
In the file: nli/index.tpl added.
    <a target="_blank" href="/help">{lng p="helpme"}</a> | <a target="_blank" href="/about_us">{lng p="aboutus"}</a>
Instead of the word, the code is displayed: {lng p = "helpme"} and {lng p = "aboutus"}

Help please, solve the problem!
Thank you.