If you're looking to lower your BG by taking in less glucose, and therefore less carb, I'd suggest that the first step is set a "target" carb intake per day. That has to be something you can do indefinitely and can actually live with. No point going for (eg) 40g/day if you find you simply can't do that. Better (I think) to have slower but sustainable progress.
Once you know what you're aiming for, then you would have to review, and if necessary exclude, all the heavy carb items from your diet. That means things like cereals, breads, pastry, most fruit, rice, pasta, almost all root veg, sugary items and anything you use that comes packaged or processed. In general by "heavy carb" I mean foods that are both high in carb percentage wise and are also items that when we eat them we tend to eat a lot of - so potatoes or oatmeal for example.
It's also worth testing around these foods just to be sure that they have the impact you might expect them to have. For example, I cannot tolerate pastry at all but legumes have a relatively small impact on my BG. There are folks on this forum for whom exactly the opposite holds. It's just how we are, and it's worth (in my opinion) finding out what affects you.
You might go further and look at the mid-range stuff next, if you feel you've got a handle on the high carb items. At this stage I decided to exclude milk, not because it's particularly high in carb but because it's something I can generally manage without - cream in coffee is fine.
I can't and won't tell you what you can eat - you really have to find that out for yourself, and there is zero guarantee that what has worked for me will work for anyone else (this is where a lot of the people who want you to pay them to tell you what to eat fail). You might find it easier to think of basing your meals on meat/dairy/eggs and green veg, and think of adding in your carb, rather than using the carb item as the meal base.
You'll find low carb and keto meal plans everywhere - the website this forum is attached to has some (but some are really not low carb at all!) and places like dietdoctor.com have more. Of course bacon and eggs is effective zero carb and doesn't need a cookbook at all. There are an increasing number of low carb alternatives around - I buy low carb "bread" rolls, bagels, and wraps from SRSLY and zero carb beer from Westbrooks. Still waiting for the zero carb potato, though.
Best of luck. I do a lot of batch cooking - just done a huge chicken and spinach curry which should provide six to eight meals mainly from the freezer. Apart from a bit from the onion, don't think there's much carb in there at all.
