Getting ready for a trip to Dakar: Gambian vs. Senegalese Wolof?

I'm a traveler heading to Senegal soon, and I’ve been picking up basics from a tutor who lives in the Gambia. I’ve noticed some vocabulary shifts and slightly different intonations—will I run into major comprehension issues if I stick to the Gambian dialect, or are there specific regional 'must-knows' I should study before landing in Dakar to sound less like an outsider?