what's the easiest way to see if I can afford to move out?

I can easily find things like rent, internet, insurance prices, but how do I find things like grocery prices? I honestly don't even know what an average grocery list might look like, are there resources to help with this? my gf and I are looking into moving out, and assuming a monthly income of ~4400 USD and rent being 500 USD, I think we should be okay, but I need to be 100% that we won't be barely scraping by or anything. thank you everyone