19 validation errors

I have a major issue my wordpress website. I discovered I have some errors with my website. I then validated my site to know what the errors were and a total of 19 errors returned.
I am just getting grasp of html coding, so I don’t really know much.
My website name is https://www.naturalperfectvision.co.uk.
Here is a link to the site where the 19 errors are located:
https://validator.w3.org/check?uri=https://www.naturalperfectvision.co.uk/

This is a first of many questions to come up relating to my site. This is the first site I am making. I hope that the questions I have will be less for the next website.