Magic: The Gathering

So I'm getting back into it, or that should be I'm going to, and have some questions.

When I last played to any extent there was the stack, that seems gone. So where are the rules these days?

I note also my dci number is now meaningless, is there no ranking anymore?

I live in the middle of nowhere (Scotland) so wonder if there is anywhere I can check up local clubs?

Also any suggestions on where to find deck ideas and where should I start, core and which expansion's?