Do I need "New SQL Server Failover Cluster installation" to run Availability groups with manual failover? I'm trying to set up a test environment here to learn more and apply this on our production environment. 

I've created and installed the Windows Cluster with CLuster manager.
Now I'm going to install SQL Server Enterprise 2014  on both machines and create HA with  then, with availability groups. The failover will be manual. They will be in synchronized data transfer. 

My question is, Can I normally install "stand-alone installarion or add..." the SQL server, or I need to use "new sql server failover cluster installation". 

I cant find anything about this on the internet.

Im going to install sql server on both nodes that will be configured in the cluster.
If you want to just use stand alone instances - which is the most common method of implementing availability groups [stand alone to stand alone] - then you only need to do a stand alone install. So, yes, you can do the stand alone if that's what you're looking for.

It is possible to use a SQL Server failover cluster instance install to also work with availability groups but it is not required.