A good starting point would be to take a movie which you really like and copy it to your harddisk. Then take out a scene and analyse it. See how it is build up, what camerapositions were used and try to figure out what make that specific scene works. Good editing is often a matter of correct timing and just showing what is necessary. Just have a look at commercials which are very short but show exactly what is needed to send out a message, filmmaking is actually the same.

For effects you should try after effects which is more suitable for that. Premiere has some abilities but is actually more an editor.

Just start editing and don't stop anymore , try to edit a scene in different ways, see how different types of music change the mood in your scene. (Never underestimate the importance of music/background sounds.)