The first thing to do is look for resources and make a shelter. Since there's a forrest with wood lying around, it wouldn't be hard to make a simple hut. Find some sturdy bits of wood or a log and gather palm trees (I'm assuming there will be palm trees) to create a simple hut to keep you out of the sun. I'd search the beach for any garbage or junk that's drifted ashore. Ideally, if you find some plastic wrap or similar material you could build a simple solar still. Metal objects and tarp would be a great find. You could sharpen the metal with stones to make a knife if you don't have one. On the first day, I'd go looking for coconuts and fruit or check rocky tidal pools for small fish or shellfish. The hard part is building a fire without a lighter. I know the method but I've never successfully done this so it would just be trial and error. Once you can make fire, you can boil rain or freshwater and solve your water problem easily. I'd probably make a spear and use that to fish in shallow waters. Once I'm secure, I'd venture further in land a little bit. It would be good to look for a place you can use as shelter and retreat back to during a storm. I guess the hardest part would be meds because you need to know your plants for that.