Any protein plus above ground veg, so stir fries are a staple for me. Instead of a sandwich I have meat or eggs and a salad. But so much depends on other factors such as A1c starting point, need to lose weight or not, medications if any.
Making drastic changes might backfire and already I get the impression you’re feeling overwhelmed.
Basically I’ve cut out carbs such as bread, potatoes, rice and pasta plus the obvious like biscuits and cakes, sugar. Others have reduced these preferring to eat small amounts, whilst others have found substitutes.
I’m sure you’re going to get lots of advice on here