This old timer needs help. What site offers the most simple way to install You Tube.(then my phone)

[Paper Roses]

I was gifted with an iPhone8 buy my kids. Wonderful. I have managed to use several functions on the phone but want to use it for photo's.

Everywhere I look on-line, the instructions are beyond my 77 year old capabilities.
Can anyone suggest the easiest to understand site to help me? I need to install YT and to somehow understand how to use my iPhone to take photo's.
I am told I have to install You Tube etc...I don't know how to do any of what is suggested from the pages I read..

Since there are no instructions with anything any longer, I have to rely on the internet.
I have such a stress headache now, I'm ready to throw the phone or the computer out the window.

Any good ideas would be appreciated.
I called my computer Guru and he did not want to help because he said it would cost me too much money. I guess it is time consuming process. He knows I am on limited income.
My computer has been updated to Win 10, no problems with the machine....it is the ancient operator.!

I may be moving soon(can't afford my town any longer) and must post stuff for sale on my local Facebook pages.
Help..if you could guide me to the right place, I would be grateful.