From this link and this link, I learnt that two-way prepositions are followed by Akkusativ when the situation involves action towards something.
Then I came across this sentence on a college website:
Bitte gehen Sie vor der Anmeldung in die Beratung im X.
Since this sentence involves motion towards a place, why are they using vor + Dativ?
"Vor" is temporal here:
Please go to the consultancy in X before signing up.
As the others have already said: "vor" is temporal here, which means it takes the dative.
Look at your sentence again. The motion expressed in it is not towards the "Anmeldung" but towards/into "Beratung". So "vor" obviously isn't involved in the motion - it belongs to the phrase telling you when to perform this motion: "vor der Anmeldung".
Incidentally, the temporal and local senses of "vor" are not that different:
indicating movement, it takes Akkusativ
indicating a point in space, it takes Dativ
indicating a point in time, it takes Dativ
[Except when you're "moving" a date to a certain point in time as Emanuel correctly points out]
Vordoesn't refer to a place/location. It is used to indicate time.