There is no official register for copyright. It is an unregistered right (unlike patents, registered designs or trade marks). So, there is no official action to take, (no application to make, forms to fill in or fees to pay).
Copyright comes into effect immediately, as soon as something that can be protected is created and “fixed” in some way, eg on paper, on film, via sound recording, as an electronic record on the internet, etc.
However, in the event of litization, it is necessary to be able to bring a proof of the existence of work to a given date. Every mean to proove date of publication is acceptable : enveloppe soleau, letter with acknowledgement of receipt adressed to yourself, publication in a newspaper. You can also have your creation registered by specialized companies : SACEM (music), ADAGP (graphic art), SACD (drama compositor), SCAM (multimedia autors), CSDEM (music edition), SAIF(pictures)…
There is no cost for registering a copyright. But you may have to pay for a mean to proove the date of creation, like publication, enveloppe Soleau or services provided by specialized organisms.
Copyright does not require renewal.
Copyright in a literary, dramatic, musical or artistic work (including a photograph) lasts until 70 years after the death of the author. The duration of copyright in a film is 70 years after the death of the last to survive of the principal director, the authors of the screenplay and dialogue, and the composer of any music specially created for the film. Sound recordings are generally protected for 50 years from the year of publication. Broadcasts are protected for 50 years and published editions are protected for 25 years.