If I understood the question correctly, "speed of evolution" is actually "evolutionary rate" or "rate of evolution", right?

To, actually, help you to figure out the exact method(s), one should know what kind of dataset you have - protein sequences, DNA sequences, morphological data, etc.

Plus, to set up molecular clock you will need to use some independent data on divergence times between at least some lineages in your dataset, obtained, for example, from fossil data.

Thanks Olga, I know DNA or amino acid sequence for molecular clock. other point is method. we have two methed, or better i say two test in molecular clock,one of them is two-cluster test and the other is branch-length test. i want to know which of them is better and why?

I want to determine and calculate rate of evolution in one group of insect,which of them help me? I select ladybird as my group of insect ,which of these test can help me for find information about rate of evolution in the group?

There are more methods than you mentioned. It is hard to give you advise without knowing what dataset is, if there is outgroup, if genetic distance can be estimated, and so on...

For starters, check the article in attachment. This is very nice paper, easy to read, and many methods are there.