Bravo Sarah, you have come to the right place and will soon have a reversal of your pre-diabetes diagnosis if you stick with this plan.
There is lots of info on this site without giving you every recipe available, just go to the search at the top of the page, type in your subject i.e. soups, and see what comes up. There is a website called http://www.thedietdoctor.com which has really good info about low carb foods, especially the veg to avoid which you might not be aware of and it also has lots of recipes.
Personally I love my salads and have one most lunchtimes but, yes soup is good. My favourite from the book is the Spanish chickpea and chorizo, almost substantial enough for the main evening meal or a lunch. There are lots of ways with stews and mince etc. One of my favourite recipes from the BDS recipe book (sarah scheniker and claire bailey and is highly recommended) is the Hungarian goulash or the cauli topped cottage pie, even a simple spag bolognaise without the pasta using spirallized courgette. There are so many to mention. There is a second search bar a little way down the right hand side called Search Recipes, which you could type in something like ‘soup’ or ‘red pepper soup’ and see what comes up.
As to what to stock up on there are lots of posts giving long explanations and shopping ideas. I will come back with specifics but searching will help you navigate the site a bit. Good luck – and dont forget to join in on any subjects that are of interest.
Also take all your measurements, weight yes but also bust, waist and hips so you have something other than weight to measure success, sometimes the scales dont move but inches do. Drink plenty of water and add a little salt to some meals to make up for the loss of electrolytes due to flushing the body and peeing lots more. So many things you will learn as you go. Keep asking questions and, as I say, keep on keeping on…