Done it just the once, it was a tandem jump. 13,000 ish ft,
It was in aid of a cancer research charity.
With it only being a tandem jump, the training was minimal, a short lesson of say 30 mins.
I am sure that if YOU intended to throw yourself out alone and not with the aid of being strapped to somebody, then a few lessons would be in order.
It was one of the best experiences i have had and was over a bit too quick (bit like sex ).
Dont worry about the dangers, lol, your more likely to get killed by a rouge goat.
Get on with it and enjoy