For the first one, just hold X/B and right. For the second one, do the same but as soon as you grab the shell, let go and quickly start running again. For the third one, hold right and run and jump as soon as the p meter is full and spam A. Finally, for the last one, hold x and right, stop at the pipe in bg, go left slightly, go (very quickly) to the right for the other coins, go down with the straight line of coins, then go to the left. You should get 10.4 or somewhere close to that.