Sorry, but I don't know if you are a man or a woman?
If you are a woman, I would recommend company, it's simply safer. If you're a man, it may be easier to meet "Natives" , if you are alone.
As a woman, I always found out it far easier to meet new people when you are already two, and -safer. Alone, you could be a target.
It's also nicer to share the new things with a friend.
Also, when you get ill in a foreign land it is better when somebody who speaks your language can support you.
When I went to the USA alone, to stay with Americans, I eventually reached a point, despite all the heartfelt hospitality, where I was pretty much overwhelmed with everything, and became homesick badly.
I would have been able to enjoy my stay much more, if I had traveled with some German friends. I know we would have had a ball, because I traveled most of Europe with fellow Germans, and it was always a lot of fun.
That's just my personal experience, and may not be relevant for others, but I always felt this way.