Thank you so much for your help!! Ok so I managed to do it how you showed me, now the logo is in the middle. But the problem is that they still want some of the navigation links to the left and some to the right, while still including in small the shopping cart and the call to action button.
Here is the website with protected password: https://indigo-flamingo-amw3.squarespace.com/
password: londoncryo
I have created now all the navigation pages so for your understanding, they would like to have:
On the left of the logo :
About
Services
Prices
Blog
On the right of the logo:
Memberships
Products
Corporate wellness
Contact
Plus on the right corner the shopping cart and call to action botton: Book
Let me know if you can still help! thanks a lot