Very interesting mind experiment....
This really depends on how many people there are. And if there is an even male/female ratio. We talking about 5 people or 100? 5 people survive, 100 people can colonize.
1. Figure out strengths of people and weaknesses
2. Gather intel on the area. what type of resources are available (coconuts, wood, sand? lol)
3. Immediately set up temporary shelter
4. Make crude hunting equipment
5. Gather food, identify edible plants as well as animals in the area
6. Spend the next few weeks surviving, replace temp shelters for more substantial ones
7. Ohh and gather water!
I'm sure not what you expected, but this is what came to mind when you asked the question.