G diaper?

I got this one diaper in a lot and I don’t understand how to use this and I assume this insert would go with it but the insert is a lot bigger than the pocket thing. I never used it and I think my baby is too big for the diaper now cause the snap lays against his skin. Anyone have success with these diapers? Can these inserts be used for other diapers. I think they are fleece and cotton but are thin? I’m so confused with all these inserts and pockets.