Excerpts only in Categories page

I wanted to have excerpts only on my categories page:
http://www.thesolodrifter.com/category/money-talk/
http://www.thesolodrifter.com/category/visa-guide/
and basically all the categories I will create in the future.

I followed the instructions on this link WordPress Excerpt Tutorial - YouTube
Tried the screen options on the top of my posts (see screenshot) and checked the ‘excerpt’ box, however it’s not working. So I tried to change some codes on Sparkling theme, however I’m not sure, I can’t find the <?php_the_content() pls. help…

oh, and I just want excerpts like this at the end " […] " with no texts or read more/click here…thanks

Hi @aiiah,

I hope you are well today and thank you for your question.

You can try achieving this by using the attached custom child theme of Sparkling theme that contains some custom code.

Best Regards,
Movin

okay, I deleted all that was in my content.php and replace it with the given codes, I just got an HTTP error 500.

http://www.thesolodrifter.com/category/money-talk/

I got help from my server and they disabled my theme for a while

"Currently i have disabled the theme sparkling by renaming it to sparkling.bk and now your domain is back online.
I suggest you to contact your developer and review the theme/code and then try again.

Please get back to us if you need any further assistance and let us know how else we can help."

I’m sorry about please bear with me I’m new to this.

What I did before:
deleted all codes on content.php and put all what you gave me, that’s when it started to go blank.

Please do not edit any theme file just download the attached child theme and install & activate it on your site. Just make sure you have already installed the Sparkling theme on your site.