UK Mum out of her depth!

I’m hoping someone can help - I’ve done extensive googling but am really struggling to find an idiots guide and am hoping this lovely community can help….

We are based in the UK and my daughter (4, nearly 5) was asked to join the pre-squad at our local gymnastics club in January. She’s been going since she was 6 months old (her older brother was 2 and attending the toddler sessions) and loves it. She’s naturally petite, flexible and loves everything about it. We aren’t sporty people and haven’t pushed her to compete, but she was asked and wants to do it so we are going with it. She trains for 2 hours a week.

She has her first regional competition coming up and we have been sent some information but it feels like a code I don’t understand! She has been entered into DevA1 - I’m guessing the “Dev” is development but what is the A1 bit? And how is it scored? The club post results of competitions but I don’t know how to interpret it and from google, it seems there’s different codes for results for different things? Any advice you can give a complete newbie mum would be so appreciated.