Tabletop RPGs. How to start?

Hi guys!

I've always being curious about tabletop games, RPG, DnD and so on. The fantasy, creativity and engagement always interested me, but I've never met anyone who played it and never being involved with it (I'm in São Paulo, Brazil, btw).

So, to be direct, does anyone has any tips on how to start? I know there are "internet based" tabletop sites/communities, but I don't know how it works.

I'd appreciate any direction! Thanks!