what kind of platform , website , should i make?

as a beginner in web programming, with no work and no degree , only the high school one , i m planning to make a platform (website) ,that can help me to win my life , i studied web programming in a special school(1 year) , and made an internship of 4 months with a company . .

the gold of the platform (website),is to provide free: services , skills , help ,etc .i tried a lot of times to make a plan ,but i failed , because i use to find it in the web , or i use to get the bad idea .

my questions are : what are the areas that will work in the future(food, music,technologies, jobs ,etc) ? how to get the good idea ? what are the steps that i need ,in order to make a good plan? when i finish my work(platform, website) completely , how to share it , and make success ? what are your advises about my proposition ?