Hi, and welcome. You'll find this forum a valuable resource, not just for those with diabetes but also for those who fear that they may be susceptible to getting it.
This section of the forum is mainly for off-topic chat, and friendly mickey-taking, but you might find the Pre-diabetes section of the forum useful, and in particular this post.
In terms of diabetes prevention, whilst being overweight is undoubtedly a concern, many people on here (including me) have found it particularly helpful to reduce our sugar intake, not just by cutting out sugary foods but also by reducing the amount of carbohydrates that we consume. All carbs turn to sugar in our bodies, so things like fruit, bread, pasta, rice, flour, root vegetables and other starchy foods can contribute to high blood sugar levels. If this sounds a bit grim, you may be surprised by the ease with which you adjust to a diet that is lower in carbohydrates. It's also worth bearing in mind that you need to replace the carbs with something else. Protein is the usual substitute, which means more green veg, salads and so forth. On the plus side there is a school of thought (again including me) which says that you can also increase your intake of fats to help in this process without doing any damage. Indeed, recent research strongly suggests that consuming saturated fats is less damaging than has previously been thought although too much fat, like anything else high in calories, will make you fatter and less healthy.
You'll find lots and lots of discussions about this subject in several areas of the forum. Have a look round, see what you think, and then ask more questions. Everyone on here is friendly and wants to help, so don't be afraid to ask! : )