Step 1: DO NOT hire another farmer (unless you’re training one for a cook) until you have 10 hearthlings.
Step 2: DO NOT have more than 3 fast growing crops per farmer
Step 3: GET a cook as early as possible.
Each food that a cook makes, aka veggy stew, meat stews, omelets ect, is worth 5-10 or more food, instead of 1:1. Veggy stew only costs 3 vegtables, of any kind, and is one of the fastest to make. One farmer on turnips or carrots can keep one 11x11 plot of those, to maintain around 30 stews at all times