If its something you only recently started considering, slow down. You don't have to apply this October, you can take a gap year. After all, you wouldn't want to rush into it and discover, once you're at medical school, that you don't like it, would you? Get some work experience, get some long-term voluntary stuff sorted, and really think hard about whether you want to be a doctor or whether you want to apply for medicine because you did well at school. There's just over two months until applications are due, so it is possible to do it, but honestly, I don't think you'll find work exp in time. And you definately can't get several months of voluntary work in before the deadline. Good luck, though.