No you are not to young to start by any means. For example check out DJ Ravine, Australian under 18 and does a lot of under 18 gigs.Some of which are in clubs. https://www.youtube.com/user/DjRavine
So it is more than possible.
Best practice is to get out there and play wherever you can. Start asking friends if you can play their parties. Maybe get together with some friends and organise a school dance or advertise in places the kids hangout. Word of mouth will get round. It is all about networking with people.
All this Whilst still doing the social media promotion Soundcloud / you-tube etc
A lot of people want to DJ in clubs but it takes sometime to get to that level. Look for DJ contests you can enter too as sometimes the prize is a set at a local event somewhere.
Good luck.
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