As Christopher said, there's a Chevron/Convenience store combo on the Cook Inlet side of the Glenn Highway (our highways have names and very few of us remember the numbers) in Peters Creek (between Eagle River and Chugiak).
If you like less congestion, you can shop in Palmer. There's a smaller Fred Meyers with a gas station down the street, and a Safeway/Carrs store with a gas station. Several restaurants ~ you'd probably love Turkey Red (local, fresh veggies, fresh baked pastries/breads, etc.), Vagabond Blues (coffee house) and Rusty's steak house. There's also a wonderful walkable shopping area along the main thoroughfare. Places like NonEssentials (gifts, specialty foods, knick knacks, accessories, etc.), Fireside Books, the Stamp Cache, Infusions Boutique clothing and sooo much more.
We're just as dependent as Californians on our cars. Just ask me, a former Northern Californian (Santa Cruz). Welcome to Alaska!