Hello Lizzie Purple-Dolphin
What are you stuck on? I hope the below will clear it up, but post again if it doesn't (all examples assume we're in C major, and I've used a / to differentiate the top and bottom figures of the figuring):
5/3 = root position. Underneath a C this would give a chord of C major in root position (count up a third and a fifth from the bass note).
6/3 = first inversion. Underneath a C this would give a chord of A minor in first inversion (count up a third and a sixth from the bass note).
6/4 = second inversion. Underneath a C this would give a chord of F major in second inversion (count up a fourth and a sixth from the bass note).
First inversion is often just abbreviated to 6; if there's nothing then it's a root position chord.
I promise it gets easier with practice, even when you start including suspensions
Best wishes
Deborah