Migrate existing website to new platform

Description

We are a tour operator and our existing website needs to be transferred to a new platform/CMS management system.
At the moment, we're undecided on the platform and would like some advice on this, though my preference would be WordPress. The new site will be managed by the marketing team with various experience in managing websites and very little coding experience. So needs to be on a platform that is extremely user-friendly, but not limited, as our website is pretty large.
https://www.latinroutes.co.uk/
We would like to keep the existing design with small tweaks. But we have hundreds of pages.
Once this project is completed we will need to do the same for our sister brand/website.
We would like to have some initial conversations and hear ideas from UX designers/Web designers/Website tech experts first and then we will decide which works best for our project.
There is no e-commerce on the site, just purely lead generation forms, but we will discuss requirements with interested parties.
The attached sample design is for our homepage and what we would like for new site.