Dual sim android phone

[Safferbeauty]

I got a new phone the other day until I can upgrade iend of Feb, got a mobicel dual sim. My main number is with mtn but the voda number came along with the phone. i got a gig free data to use in 3 days yesterday but how do I switch to use the data on that voda sim card for whatsapp etc and can my whatsapp number be the same or do I need to change it to my voda number?