I have a ~100 lb GSD mix. He ate astonishing amounts of food through puppyhood. I think he peaked at 8 cups of TOTW a day. Trust me, you do not need to worry about food going bad.
He's two now, and eats a scant four cups of Blue Wilderness every day. I have a large plastic bin (here's the Amazon listing) and get 25 lb bags of food delivered via Chewy every month. It's very easy.
Just a few ideas!
Replace the metal shelves with something closed-in. There are lots of inexpensive options from Ikea, something like https://www.ikea.com/us/en/p/ivar-2-section-shelving-unit-w-cabinet-pine-s39248359/. Could also check out Ikea's Besta.
Get some storage bins for dog food to keep it fresh and get it off the floor, something like https://www.amazon.com/Bergan-50-Pound-Smart-Storage-Large/dp/B000MW8JYU/ref=sr_1_25?dchild=1&keywords=food+bin&qid=1623137383&s=pet-supplies&sr=1-25
Take a sweep through your kitchen cabinets with a goal to recycle / donate / throw away at least 1/4 of the items. Chances are there are expired boxes of food you know you're never going to eat and cookingware you never use. Try to stop treating the top of the counter / floor as the "home" for things. If there isn't a place for something and you're not sure if you're ever going to use it, it's OK to throw it away / donate it. You won't miss it. If you do end up missing something, chances are you can replace it for <$20, and it's worth more than $20 to have you kitchen counters free and clear and not cluttering / stressing up your life.
Consider getting pot + pan racks / interior shelves for your kitchen cabinets that will help you organize things without stacking things directly on top of each other. Label makers and bins of different sizes are also helpful.
Think about what you want the space that's currently an office to be as part of your home and try to think about changes you could make to improve the experience of the people using it for the intended purpose. If it's going to serve as an office space, it may help to make changes to the furniture so that it provides a way for managing cables, plugging in phones in a convenient way, and storing desk items like post-it notes. What do you think about an L-shaped desk with some storage? Doesn't have to cost a lot, Wayfair has a few <$200.
I put dry dog food in a plastic vault like this one. It's supposed to keep the food both fresh and safe from meddling puppies. (: