Hi,it will be tight to visit these two sites in just 1 day. You can go from HK to shenzhen by air and take metro to those two places

Dear Mrs.Anita, is better to divide your day so that is not too tired for all at one time. You can stay at YaFeng Hotel which is just opposite Splendid China that cost Rmb260/nite. Either one you can visit 1st since is just nearby which is just 1 stop MTR station.
Splendid China station is HuaQiaoChen and WOW is the next station which is the last station if you coming from Lowu Shenzhen. Both also have performance during the evening/night so it better to visit around 4pm where you can also view the show.

Dear Mrs.Wijaya, from HK airport you can take the airport express to Kowloon station and from there you can take a FREE shuttle bus to HungHom station where you then take a KCR train to Lowu station which cost around HKD30 and then once you are out you may go down to the basement of Lowu MTR station that can take you direct to HuaQiaoChen (2nd last station) which is Splendid China or straight to the last station which is the Window of the World and it cost Rmb5 for the 1 way trip. If you plan to visit both at one time is fine if you are fit to walk atleast 4hrs for both places. Each of the place cost Rmb120/person.