I think your explanation is too generic to get good advice. You should expand on what you want to do if possible.<p>I think the best way I can explain it is that this feels the same as contacting a caterer and saying "I have an event with people, what should I serve?" Any good answer would require knowing the type of event, the venue, dietary requirements, number of people, budget etc. Same with you task, but we need to know more about skills, specific functionality, goals, etc.<p>The actual answer, in my opinion, is that hosting, software stack and secure storage of data aren't a big concern at this point. You have an idea. Turn that into a plan including all the features you think you need to launch a first version of your app. Remove 50% of the features. Remove another 50%. Talk to potential customers. When you have a solid plan, then you can start worrying about how to make it happen. Then build it using whatever software stack you know best.