This is going to cost a fortune, and you are going to be caught out one day.
Start gently, with some crudites (sliced carrots, cucumbers), strips of pita bread and hummous. That's a meal, for both of you!
People have mentioned jacket potatoes: that's good, but you just have to remember to plan it.
Cook bolognaise sauce with: chopped onions, mince, bottled passata/tinned tomatoes, red wine. Rosemary is also nice. If you can, add mushrooms, and chopped peppers near the end. Very tasty, and it is a "recipe" which can be changed in various different ways.
Make some couscous (by pouring the indicated amount of boiled water over the couscous and covering the bowl). Then chop up tomatoes, cucumbers, spring onions. Once the couscous has cooled, mix in the salad, and you have a primitive tabbouleh!
To make fajitas (baby can eat a version of these, and will be able to eat this as a toddler): buy the fajita wraps, yogurt/sour cream/creme fraiche, onions, peppers, chicken (breasts are easiest to cut), hard cheese (e.g. cheddar). Cut up all the veg and meat (separate board for the meat). Fry veg and meat separately, and place in separate bowls to add to your fajitas. Heat the wraps according to the instructions, and start assembling your fajitas to eat! (I know there are other things you could add, but this is simply, and baby will eventually be able to join in).
These dishes use different techniques, but techniques which are fairly easy and which show you that it's not too bad, cooking, and saving some money while you cut the salt and other things added to ready-made food (for yourself, as well as for children).
It is worth getting a good knife and a few cutting boards, particularly if you're going to cut meat.
Hope this helps, saves you a fortune, and makes you feel more confident!