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hello, i am new and setting up a blog, i´ve a bulk of questions i have not found clearly on my searches for answers

1.- one must own a domain and a hosting plan and use WP ion those servers to be able to have one´s own google adds?

2.- is it possible to install plugins if i am only the owner of the domain and i have WP mapping it?

3.- where can i read about the differences between hosting WP on my own server or the standard one

thanks

happy holidays