New PPL so hardly the voice of experience, however the grass strip I learnt at has a displaced threshold on 24, which starts with an upslope and then a bump just before the runway levels out at the threshold, and you usually hit that at around 45kts when two up in the Robin, when you actually want to be rotating at around 55kts.
The technique I was taught was to accelerate with gentle back pressure to take the weight off the nose - assuming you don't have too much back pressure when you hit the bump you grab a bit of air but it settles back down again quite quickly, then you can rotate as desired.
You certainly don't push the nose down at any point, just manage the level of back pressure to maintain the right attitude. If you're solo and get a good run up the slope you can just get launched off the bump
