Some good advice on this thread, but also some rubbish. Just like always
1) Learning to fly a twin is probably one of the most rewarding things a private pilot will ever do.
2) It would probably be a good idea (as someone else suggested) to get a few hours in a complex single first. Get the hang of ONE constant speed prop, gear which goes up and down PLUS of course the extra speed before transitioning to a twin.
3) Warn the bank manager. Few things burn up cash like a twin - although in my view, few things are as worth the money
4) A twin brings a significant added margin of safety over a single BUT only if you're current. An un-current multi engine pilot is a menace to himself and others.
The best way to keep current is to take your friends shopping in France. It's perfectly legal to cost share (up to a maximum of four ways!) - so get three friends, have a great day out in France and bring back as much cheap wine as the weight and balance calculations allow! :-)