Calculus taught in USA and Canada can be called "Elementary Calculus" that is accessible for some, if not many, well prepared primary school students. Some people can self study this level of calculus before grade 1 but is considered as "exceptionally smart kids". You do not need to worry if you did not learn calculus by yourself in primary school. In fact, most students do not do any self-study about math and they just passively learn calculus at schools after grade 10. At some universities or colleges, they even offer high-school level math courses for those not well prepared.
Mathematical analysis, on the other hand, is considered as freshman level calculus, taught in countries, for example, Russia, China, etc,. At US or Canadian schools, this may be called "advanced calculus", which is not really advanced at all.
As you can see, our undergraduate math education is at a lower level compared with countries like Russia, China. Our tutors and resources may help you to bridge the gaps, help you getting a smoother transition to graduate level mathematics. Calculus is one of the foundations.
What we can help:
MATH AP Calculus, MATH IB Calculus high level and all levels of undergraduate calculus courses.