I certainly have. I got into competitive play in 2010 and have been buying a bunch of the packs since then, because I've been hearing about all sorts of useful Trainers in those sets.
You could probably try competitive play at 13, but your age group is a very competitive one at most tournaments, from what I hear (Seniors is for those who are between 10 and 15). It'd probably be an interesting experience to get the chance to play against others, I'm sure, but winning would be pretty tough.
I collect everything, really, but my favorite type has kind of always been Electric types.