We stay overnight in the truck… Partner has his “own” cab and only uses that one. It’s kitted out with microwave and fridge. Our weekly shop consits of microwave dinners, snacks and fruit plus bottled of flavoured water. In addition to that we buy still bottled cheap store labeled water for making tea and coffee, cubed sugar as this is less messy when make a cuppa, milk and anything else we fancy that can fit in the fridge or storage compartment. Microwave oats are a great breakfast.
Wet wipes, kitchen towels and plastic bags are a must. Mouthwash and toiletries and a towel. Bedding or sleeping bag… And pillows. Spare clothes for the week / nights out. Cables, charges and tablets, sat nav and hands free for the phone.
Truck apps to help find truck stops, Google maps to see hotspots of traffic and spottily for good music when the radio is crap or you loose your favorite channel depending where you are. Note pad, pen, change, and diary… Oh yes and a versatile small tool box, torch, gloves, hi vis vest and hard hat. Last but not least, that I can think of right now, a small box with paracetamol, indigestion tablets, Imodium, plasters etc.
Hope this helps