Alignment fungtions

Alignment function(s):
I do have following issues:

When i import a part i.e. step-file how can I give that part a clever coordinate-system and if done how can I use this part to align it with for example the main-coordinate system x-y-z?

When I align surfaces with the given function i loose all other pre-set figures as the alignment go to surface-surface but with the points I choose or took for that function?

Thank you in advance for any support.

Regards Markus Burger