how do you replace banner photo

Hello, I’m using NU2013, I have two problems that I can not solve.

I state that I put into practice the instructions of your tutorial

1) Only in this page, when I attach the URL in a word, the selected text becomes small
https://www.psicologacontinovara.it/wp/attivita-clinica/

2) only in this page, I can not leave a blank line (line spacing) between paragraphs
https://www.psicologacontinovara.it/wp/conflitto-genitori-figli/

Thank you so much if you can help me
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