I am a new user to cachyos and linux in general

Issues & Assistance
15

No worries.

So now we are sure it is fastfetch.

So you can execute it any time;

fastfetch

And if you still want it in your rc file then .. edit the rc file and add it there.

Note: ~/.zshrc means /home/$USERNAME/.zshrc.

An example of the first handful of lines (of a bashrc);

#
# ~/.bashrc
#

# If not running interactively, don't do anything
[[ $- != *i* ]] && return

fastfetch

Save the file .. then just open a new terminal to see if it worked.