What is the total magnification using high power?

This depend on type of microscope and in particular which specific model it is.

High power may refer to the microscopes ability to enlarge a lot, not that it actually consumes power.

In this understanding of the term, the microscope in question might have two separate but combined lenses of which the total magnification can be calculated from.

It may have an objective lens and an eye piece lens, both of which that might be changed in order to achieve greater or less magnification.

Typical configurations are:

Objective lenses of 1, 2, 3, 4, 10, 40, 100X magnification

Eye piece lenses of 5, 10, 15, 20X magnification.

If your microscope fits this configuration, then the maximum magnification you can achieve is 100x20, a magnification of maximum 2000 times.

The problem here is the wavelength of visible light. It does not allow for more magnification than approx 1500 times and even this is not a very detailed one.