Tips on eating healthy when your limited?

So my boyfriend and I live with his family, we have our own room and bathroom. We do our own grocery shopping, we have a mini fridge and a small desk where we have our snack and dry foods. I need to start eating healthier because right now all we eat are TV dinners or we eat out. We don’t always have time to use the kitchen to cook or prep meals. Do y’all have any tips or like healthy frozen meals we could start buying? We basically need something quick and also healthy obviously. We sometimes are able to cook ourselves a nice dinner but we work all day and into the night so when we come home it can be difficult for us to start cooking a nice meal bc his family is using the kitchen or we are just too tired.