Yes it can be very confusing, I was diagnosed 3 months ago and even though I already knew a fair bit as my mum is Type 2 it was pretty overwhelming.
The good news is you don't have to change everything all at once. As you're only on metformin, your HbA1c is probably much less than mine was at 113 so you can make gentle changes at a rate that you can handle.
I ditched cola immediately, and to my surprise don't miss it at all. I get my caffeine from unsweetened tea and my fizz from sparkling water.
Crisps were more of a struggle, I still have them about once a week but try to stick to one pack or at most two at a time now. Only you can decide whether to cut down, substitute or eliminate them completely. Salted popcorn, pork scratchings and lentil/ hummus chips are lower in carbs than "normal" crisps if they work for you. I haven't found a decent substitute yet for a salt and vinegar crinkle cut crisp!
Takeaways are a bit more complicated, some are better than others but none will ever be quite as healthy as a home-cooked meal. Sometimes they're necessary for various reasons (and enjoyable!), personally I avoid chips/ bread/ pastry/ rice/ noodles and choose something like kebab with salad or a Chinese/ Indian with meat/ fish and veg, nothing sweet or sticky. Very much depends if you're ordering for yourself or sharing with family.
Good luck with your journey, it's a marathon not a sprint and we're here to help or just cheer you on if you need it