Suppose I take my centrimax vitamin after an hour of taking my adderall xr 20mg pill...Would it interfere with adderall's absorption? Will the vitamin c interefere with it or not?

Basically, is it safe to take vitamins with your medication(in this case...adderall xr20mg)? Any benefits from doing this?

The vitamin C could be in the from of an ascorbate salt. And want be acidic.
If not if the calcium is in the form of calcium carbonate it would neutralize the vitamin C anyway. Magnesium oxide could also. Its unlikely to be a problem.

You could do an experiment:

Crush one of your vitamin/mineral tablets to a fine powder add 1/2 cup of water and boil in a coffee cup in the microwave for a minute. Allow it to stand a few hours(ideally with stiring). Next add a pinch of baking soda. If it fizzes its acidic. Keep adding baking soda slowly till fizzing stops would give and idea how acidic it is(titration).