Hi, Kailey
I do not know if you have tried any of the plumbing instructions on this site - if you had, you'd likely have flooded the house.
As a regular DIY plumber, I can see many mistakes in it. The first one is that there is no mention of turning off the stop-cocks before you start on most of the recommended projects
Also, the terms used are not the terms in common use among plumbers. Plumbers putty is normally "Plumbers Mait". Teflon tape is normally "Plumbers Tape" or "PTFE tape".
But above all, I think that it is irresponsible to recommend a website which advocates the installation of an electric shower as a DIY job with a few paragraphs of guidance