Hey friends!!

So Im currently booking my first trip to Canada and I just need some help because Ive heard a lot of places I need to visit but Im unsure how much time I need in each and which I could cut out in order to see what I would want to see most. Information is as follows;- My flights into and out of LAX are currently booked for the 10th of July 2016 to the 10th of August 2016. These flights cant be changed as they were a credit for a trip to the USA I booked last year, but Ive been to the states before so time to do the North! I want to spend at least 8-10 days in San Fran and New York, Ill probably do both of them at the very end of my trip (Ive been to both cities before but I loved them and want to do them again), if need be I can not go but pretty sure I left my heart in SF two years ago so I at least want to go there. I plan to spend time on both the west and east coasts, and I will fly between. I will probably train between major cities.
The places Ive been told I should visit are Vancouver, Whistler, Banff, Calgary, Toronto, Niagra falls, Ottawa, Montreal, Quebec City, ST Johns and Prince Edward Island. Fitting all these places in it looks like ill only have 2-4 days in each place, which probably isnt enough time. I definitely dont want to only do one coast, so Id appreciate some advise on how to hit both coasts but see all the best places!

Information about me;- I am a 23yo female from Western Australia. I travel a fair bit. I am fit and enjoy being adventurous, but I have a terrible fear of heights, particularly on unstable surfaces so I am a bit concerned about that. I plan to stay in hostels as I am travelling alone. I wake up early and dont drink or party too much, more of a laid back traveller and enjoy a nice meal or going for a walk and enjoying the sites.

If you need me to answer any questions please throw them my way. Thank you in advance for all your help!!