Get a few hours under your belt post-PPL, but then go for it. Maybe sit right seat with a more experienced pilot who's going cross-channel, to see what's involved, first. But, you do not need to be some kind of sky-god to fly across the channel; I only had 150 hours total time when I hopped in a C172 and flew it from Florida to California and back! Looking back, I'm quite pleasantly surprised that they actually let me rent their airplane to do that..!