I plan to go Lantau Island first then go to to Victoria Peak, what is the best way?

You are going to visit Ngong Ping 360 on the island, right? After the visit, you may take the cable car down. Walk to Tung Chung MTR Station, take MTR Tung Chung Line to HK Station, Exit E2. Then, walk to the Garden Road Peak Tram Lower Terminus, and take the tram up to the Peak. :)

Thank you for your advise. This is exactly what I'm thinking for one jampacked day in HK. How long (time-wise) is the commute between the two attractions?

It takes about 25 minutes to ride on the cable car. Then, it takes about 25 minutes from Tung Chung Station to HK Station by Airport Express. Afterwards, it takes about 15 minutes to ascend the Peak by tram. So, the time is about 70 minutes to commune between the two. :)