Welcome to the forum.
It is a bit daunting when first diagnosed but you will find lots of helpful people here to guide you.
If you give a bit more information about your situation it will help people tailor their advice. So a few questions
What is your HbA1C that has led to your diagnosis, it will be a number above 48mmol/mol as that is the threshold for diagnosis.
Have you been given any medication.
Some examples of typical meals you have will help to make suggestions about what you will need to do.
As it is ALL carbohydrates which convert to glucose then it is those things which are high carb which you need to reduce in your diet. So things like potatoes, bread, pasta, rice, cereals, pastry, tropical fruits as well as cakes, biscuits and sugary drinks are things to be watchful of.
It might sound as if there is nothing you can eat but basing meals on meat, fish, eggs, cheese, dairy, nuts, vegetables, salads and fruit like berries, with only small portions of those high carb foods.
How much you need to do depends on where you are in the diabetic zone.
Have a look at the Learning Zone (orange tab at the top) to get a better understanding on how to manage your condition. Please feel free to ask any specific questions.