Welcome Debbie
There are several kinds of diabetes - the most common is T2 at about 90% of diabetics, then most of the rest are T1 or a number of other types such as Late Onset Autoimmune Diabetes in Adults (LADA) or T1.5, Mature Onset Diabetes of the Young (MODY), Monogenic, T3, T3b and so on. Hopefully the consultants can narrow down which type he has but in the meantime treating him with insulin as a T1 or T1.5 is probably best.
Anyway, I'm glad you have joined and I hope you will find helpful information and support here. I'm sure we can learn from you too.