I'm in the same position as you, albeit younger. Been playing drums for a good couple of years, still am, but in my spare time I'm messing about on guitar and singing etc.
As for lyrics, it's definitely something that improves over time. Influences come from anywhere really. To me, vague lyrics are kinda fun. Trying to write something that speaks on different levels gives the song a new layer I think. I also love thinking and writing lyrics that have certain concepts to them. Stories and things like that are awesome to write about.