When my kids were in college I would put together simple meals in shopping trips and have them delivered via Instacart with easy instructions. To be honest, I would even put together little spice packets in clearly marked ziplocks and mail them for stuff like stew, chicken soup, cacciatore, tacos.
For example, slow cooker shopping from Wegmans it would be:
Stew: Stew meat, mini potatoes, baby carrots, beef broth, ketchup and egg noodles (my spice packet with paprika & marjoram)
Cacciatore: Minute rice, Chicken thighs, tomato sauce, mini potatoes, capers (my spice packet)
Ground beef or chicken,beans, tomato sauce, frozen chopped onion and Dorot frozen chopped garlic (my spice packet from simple perfect chili)
Tomato sauce can be made in a slow cooker (spice packet is ok too)
I ALWAYS sent 1 or 2 roast chickens with groceries on a Friday and at the end of the week the bones would go in a slow cooker then strained for chicken soup with leftover veggies, my spice blend and pasta of some kind.
Wegmans also has an extensive list of premade things like a stuffed pork chop or a premade meatloaf that can be baked in their metal container, Shop-rite has lots of this too and they are all over NJ. I'd suggest you look online at local stores, you can probably custom make something that works for you. I always used my own phone number and asked they call when things are dropped off so I could keep tabs on it being brought in.
If your dad needs more help ask the local churches, this is how the family found someone to assist MIL, they have a lady that comes in to cook lunch and dinner every day but who is also a sort of companion who keeps an eye on things.