Is flickr the best place to have photos on line to share/download etc?
There are a couple of places you can share your work, Flickr, Instagram, 500px even Facebook. It depends on why you want to share.
I personally use and like Flickr mostly because it was the first site I came across and started to use but now I carry on with it because it is to photography as LinkedIn is to social media. Instagram is more like Twitter or Facebook; it’s a little less about the images and little more about the social status of those posting.
Flickr is a good community and has plenty of opportunities to connect, get input and advice, develop your ideas and explore other photographer’s work.
Regarding copyright, I think that anything you produce is automatically your copyright. You’re real question is how do you enforce it. It depends on what kind of images you’re making as to how concerned you should be about that. I never even give it a second thought personally. May I suggest that unless you’re producing stuff that’s seriously good, it’s not something you need to worry about?
This site might help you review which sharing site is best for you:
Review of photo sharing site