How could I market my business?

The first thing you need are holiday homes on the site.

And then you need a marketing budget. £ 1000 / month would be a decent amount to start. There are a large number of competitors, all with abundant pockets. If you do not have the funds to compete, you do not have a business.

And anything that contains 4U in the domain name is virtually doomed from the start.

Sorry to be so negative, but you do not have a business. All you have is a basic WordPress site.