taking bullet train from hangzhou to shanghai about my luggage i have to take it on the train.

Firstly, it is fine to take your luggage onto the train, unless it is huge.
As for the train ticket, there is no need to book in advance in normal weekdays, as many trains are in operation. However, if you happen to travel during peak season like May Day, Chinese National Day holiday and Spring Festival, train ticket booking will be necessary.