Welcome to the forum.
What you need to be doing depends on where you are on the diabetes scale and what medications you may be taking.
Your HbA1C result will tell you where you are and therefore how much work you need to do.
The threshold is 48mmol/mol so if only just over that then some modest changes may be all that is needed.
Reducing carbohydrates in your diet as it is all carbs that convert to glucose but the big hitters are not just the obvious cakes, biscuits and sugary drinks including fruit juice but potatoes, bread, rice, pasta, pastry, tropical fruits and breakfast cereals. It may sound as if there is nothing you can eat but basing meals on meat, fish, eggs, cheese, dairy, vegetables, salads and fruit like berries with only small portions of the high carb foods.
It does not mean you can have NO carbs but modifying your intake.
This link may help you with some ideas.
https://lowcarbfreshwell.co.uk/
Many people do find low carb successful but others choose low calorie, or shakes based regime to give them a kick start if quite a long way in the diabetic zone and they need to lose weight.
The important thing is to find a approach which suits you, which you enjoy and is sustainable long term.
Do come back with any questions you have but a bit more about your diagnosis will help people make suggestions.
You could also look at the Learning Zone (orange tab at the top) as there is lots of info there.