I feel like my biggest struggle with my dog was training on walks. He was terribly reactive, had poor leash manners, and was likely under-socialized when I got him at six months old. Eventually, he learned to ignore distractions and reactions were few and far between. I also learned to accept him for who he was and not take misbehavior personally. Hopefully you won't have to deal with that, but it shows the importance of taking time to train your dog now while he's young and allow him to experience new things! Now, though, we live in the country on 22 acres, and walks are no big deal because there's nothing to react too...and if he does react it's usually for a legit reason!
Another tidbit of advice, especially for this puppy stage, is that this is by far the HARDEST part of owning a dog. It's a disruption to your usual routine, things have to change, the dog doesn't know how to behave, you have to deal with potty training. Remember that all of this is temporary. It's okay to feel overwhelmed! If you remain consistent, in a year or two you'll have your perfect, well trained companion and life will be a breeze again.
As for "green" and "organic" things, know that they will be very expensive. For example, an organic Castor & Pollux food is between $50 and $70 for an 18 pound bag depending on the protein, it seems...be realistic with your budget! A good food is something you can afford and that your dog does well on! Learn about food and treat ingredients and what it means, too. Some foods are very expensive but their ingredient label shows they're likely not worth the money I order food from Chewy, which has a bit more selection then local pet stores and is typically less expensive.
