Is it true that Canada has more British influence and culture than the USA though the two are similar?

To be honest, I think you have made some astute observations and have basically answered your own question. Canada was a British colony longer than was the USA, so retained more British influence. I also think that, with the demise of the British Empire, Canada and England have become more similar in politics and influence - as middle powers rather than super powers. The USA's status as the world's biggest superpower gives it a unique identity and a type of national patriotism that we just don't see in the UK or Canada.