Question regarding website platform?

Hi I have a query about website platforms. I don't know much about this field so please

1, ive been told WordPress is the best platform for SEO, is this correct?

2, if I had a nice site designed in PHP, can this simply be converted into WordPress and still look exactly the same? And will this be better for SEO

3, what is better, WordPress or PHP?
4, what are the advantages and disadvantages of WordPress and PHP?

Thanks

WordPress is easy to customize and use. In the end, it will be easier to make changes, adding new content/etc compared to custom coded PHP site, especially, if you are not the one who wrote the code.

From SEO point of view as well because you can get couple good free plugins and sort the whole on-page SEO/meta's out. You would have to code it from scratch for your custom PHP site which begs to ask - why invent wheel and I doubt the interface will be as friendly as it is in WP.

As for conversion - doubt you will be able to do 1:1.

I would stick to WordPress.