For the Nollie to nosepress you should be able to Nollie and nosepress separately. This is a cool easy trick and if you can ollie high and over stuff and then land in a big tailpress it looks cool.

First, put all your weight on the nose off your snowboard. And try to lien forward as far as possible, but without falling. Then bounce off your board with both feet. It the same as jumping up. When you jump up should feel the board bend a lot. This means you are don't it correctly. When your in the air. Level out your board and land back in the snow nose first. Then put all your weight on the nose off your snowboard. Make sure the rest of your board doesn't touch the ground. Then and try to lien forward as far as possible, but without falling. It might take a long time to get your balance perfect, but after it if really help you with lots of things. Also, when you are leaning forward, do it straight back, not to a side. Then hold your balance as long as possible and then go back flat on your board.
Good luck!