Is there a unified way to footnote? I keep sifting around online and there seems to be a variety of different footnote methods.

I want to make proper citations for each:

Please show how each would be written out.
The last one is the book the rest are online resources. Which I hope are credible this is a college level history essay.

Also, what should I do with the footnote when I am quoting the same source over again but it's in a different section of the same web recourse. should I put the same footnote twice or is there another method to this?

Thank you