Im trying to find a nice progression to transition from Bb to C. what chords or progression should I use so that it won't sound choppy?
There are a couple of things you could do. Try this:
You could do a 2-5-1 in the new key of C
Bb F/ D F Bb ending chord in old key
D A/ C F A 2
G D/ B F G 5
C G/ C E G starting chord in new Key of C
You could try a 5-1 walk-up in the new key:
Bb F/ D F Bb
G / B D G 5
A / C E A 6
B/ B D G 7
C/ C E G 1
Hope this helps.