U.K. - Hong Kong - Hanoi

Hi my self and my partner are uk citizens traveling to HK for 4 days, then flying over to Hanoi, we understand we need a visa for Vietnam as we are in Hanoi for 5 days, Ho chi min city for 5 days and then Phu quoc island for 8 days but is there anything we need for HK or anything we need to do because we are traveling from HK to Hanoi?
Thanks in advance