I am going with a group of friends. I recommend uber or cabs, public transportation will be a mess.
Golden circle should have a nice view, so going too early might not be that great of an idea unless you want first row.
Mind that people might be a bit aggresive, last I-days got a knife shown because i was at the barricade and some dude wanted 3 spots for himself. security was quick to kick him out tho