Confused between vue, ember, angular and react. Which one should I learn?

None. You need to find the framework which was written yesterday, otherwise you will risk your site not being compatible with every brick out there.

If you don't know which one is right, then you aren't ready to write an application... but you are ready to try each of them.

@sheriffderek best answer yet

I got stuck with react because it seems that I can develop faster with it.
Angular and Ember seemed a bit heavyweight to me. And i never had a look on Vue.

It depends on what you want. If you want a front end library then Vue. If you want a front end framework which can do a little more ( after you install like 50 node packages ) then react, if you want a simple full front end dev platform, then angular 2.