How cool would it be to just kick back on a deserted island with only you and maybe a few loved ones around you for a week! That would be an awesome vacation but what about longer? To be honest the island would have to be big enough to grow crops and live off of otherwise shoud you get stuck that wont end very well.
It should have a water source, like a lake and a well. Should you need water you can always put plastic bags over the leafs early over night and the humitity will draw down into the bags. I would get some barrels for collecting water even if you don't use them it's good to have them on hand filled up ready to go and maybe even a water tank below ground a nice plastic or concret one would do nicely.
Now for the food, a green house and a root celler would be a good start even if it grows wild you still want something to fall back on being so far away from evryone else. MRE's are great to store but the taste isn't a factor when servivel is at stake. Having fresh fruit all over the island is #1 coconuts to bananas serve well for water and food however you still need some nuts and other means of protein. Chickens are great for this and they lay a lot of eggs if you have a coop setup.
The point isn't to live off the land but to have that in case you have to and to be honest fresh food is better then most in the market in todays world. Remember to store seeds away just in case you need them down the line at some point, if stored properly they will last forever.
Comunication is another big deal, you will need backup for your backups and always have a backup for that. With todays tech you should have the ability to get what you need but it will cost you some money. Most people who own islands use it for vacation spots while others live on them and never really go out beyond it unless doing shopping or something everyone and a great while, try not to be that person as most the time areas on the shore that have islands with in the distance are for the most part friendly. Also make sure you own a spot on the mainland sometimes you need a car and unless you have a very big boat or can drive across water(a few cars can do this) its just a smart move. Keep dreaming big and never let anyone steal that away from you EVER!
You have a minor grammatical mistake in the following sentence:
It should be better than instead of better then.It's funny because you claim to educate people however not smart enough to send a private PM and do it with respect. You don't know how to teach people and lack the humanity it takes to be a real teacher. Next time use # with a space (# message) and then your message in steemit memo transfer section so it's private and people will be more willing to listen to your teaching.