You're at the point the bulk of us started from. And quite a few of us have managed to wrap our heads around it eventually (It does take a while, especially after a shock-diagnosis, as that throws one for a loop). So do take your time and learn what you can.
https://josekalsbeek.blogspot.com/2019/11/the-nutritional-thingy.html is a bit of a quick-start-guide I put together, with everything I wish someone'd told me when I was just diagnosed and honestly, scared out of my mind. Take away some hope from that: It does get better and diabetes can be managed perfectly fine. Especially if you're willing to work at it. You'll be okay.
Hugs,
Jo