Mr.Stanley,
You can take flights, trains or buses from Shanghai to Huangshan. For flights and trains, please use train/flight search function on this website:
https://www.travelchinaguide.com/china-flights/
https://www.travelchinaguide.com/china-trains/

For buses, you can take buses at Gonglinglu Bus Station (公兴路汽车站), Beiguangchang Bus Station (北广场汽车站) and Xujiahui Bus Station (徐家汇汽车站). Remember to buy tickets from Shanghai to Tunxi (Huangshan) so that you only spend more than 4.5 hours on the high way.

After you arrive at Tunxi, you can take buses at the bus station near the railway station. The ticket costs CNY 15-18. It takes 45 to 75 minutes.

If you want to have much fun in Huangshan, better stay there for a night since you can not finish those attractions on the mountain just in one day.