Add contact details to header on new website

Hi,

I have two small alterations I would like to make to my website header. I’m hoping someone could assist me with the code and where to place it.

1 – I would like to add a simple line:

Text us now on 07123 456789!

to the header on my website. I would like to do it in a stand out font in a different colour, central on the page and in line with the search field (when viewed on a large screen).

2 – When the website is viewed on an iPad, the navigation menu changes to the three small lines as expected. However, the small lines are appearing over the top of the search field.

The website is https://www.mascari.co.uk

Many thanks for any help.