What technology should I use to create this certain web app?

I want to create a web app which main functionalities will be: -Few users can connect to the same instance of an web app -There will be dashboard in which points and places of certain users will be displayed -There will be one admin that can assign points to the users. -Data base from which admin will also assign some let's call it "values" to the users. What kind of technology I can use here? I know some c#, java and also some html but I have never create a web app. I am not scared of learning new thing. I read about some .Net but I am not sure if it is the best option for creating it. Thanks a lot for your recommendations.