first for all welcome to the community!
you can get influence by purchasing a package or items from the store
i forget what the threshold is to unlock being able post avatars, signatures, images, links etc - be patient and i'm sure somebody will confirm it for you
a basic Elyrian Package should unlock most if not all of it for you is my unofficial thought
this was put in place not to discriminate against those who hadn't backed the project, but rather because we at one time here on the forums were experiencing huge amounts of spam threads being generated by bots with free accounts etc