Or, if you want to go the with the 'writing reviews' way, then you can just start up a blog, there are 10,000* free services to do so. Wordpress, Blogger, etc. Once you start getting followers (the hard part, usually requires you to market yourself to like minded people) then you can start trying to direct the attention of existing anime review sites to your blog, they may like (or not like) what you're writing about, how you write, etc, and may be willing to let you freelance, once you are freelancing, really, really apply yourself and they may be impressed enough to let you become a full-time writer. Just keep in mind that these sort of gigs don't pay very well so you either a) need to expect to never eat food again or b) work part time for a supplemental income. Just do not expect all this to happen overnight, or even within a month, it could take a long time. If you are truly serious about this, your own ambitions, skills, and interest will open the door for you. The trick is to just not give up when it looks bad.