You could practise a few basic dishes thatare versatile.
One I love is chicken tray bake. You can use thighs with skins on or whole legs. It's incredibly easy to prep and the variety is endless. All you need is a deep roasting pan. I also put down greaseproof paper so it's easy to serve and clean, but you don't have to.
A few examples:
Fresh herby chicken traybake: Put the chicken pieces in a big bowl. Add 1-2 tablespoons of olive oil (or other cooking oil) Add the roasting dish. Add the zest and juice of a fresh lemon, some garlic granules or a squeeze of garlic paste, salt and pepper and a bunch of fresh, washed, roughly chopped herbs (tarragon or rosemary or oregano) Add some small potatoes, thick rings of fresh leek. Toss until the chicken and veg are evenly coated then put in a roasting dish and spread everything out into an even layer. Pour in a small glass of white wine or a small wineglass of water. Bake for 45mins at 200c. Serve with peas and carrots or salad.
Mediterranean traybake.
Toss chicken in a bowl with generous squeeze of garlic paste (about 8-10cm) salt and a sprinkling of dried chilli flakes and dried oregano or Italian seasoning or mixed herbs.
Add some chunks of red pepper, peeled quartered red onion, black olives, chunkily cut courgette and aubergine and some cherry tomatoes. Tip into the roasting tin and bake for 45 mins at 200c.
Serve with crusty bread and salad
Spicy tray bake:
Mix 2 tablespoons each of mango chutney, madras curry paste, water and corn oil. Add 1 tablespoon of either lemon juice (can be from a Jif - doesn;t have to be fresh) or lime juice (same) or white vinegar and one tablespoon of brown sugar or honey. Mix until is is a thin paste then coat the chicken legs in it. Put in roasting dish with peeled quartered white onions, diced sweet or white potato chunks and cook for 30 mins at 200c covered in foil and then add a mug full of frozen peas and stir them into the juices, and a bag of washed spinach if you family will eat it. Cook for another 15 -25 mins with foil off, until the skins are golden and bubbling. Serve with rice or naan.
You can do simple dinners like filled fresh pasta (tortelloni or ravioli) with bagged salad, drizzled with pesto and grated cheese. - That's simple.
If you learn to make a good tomato-based sauce with soffrita (finely chopped celery, carrot and onion, cooked on a low heat until soft) then add chopped fresh garlic or garlic paste, diced red peppers (or any other peppers) - and optional - courgettes/aubergines/chestnut mushroons, a couple of cans of chopped tinned tomatoes, a good splash of red wine or a tiny splash of wine vinegar, a heaped spoonful of dried herbs such as thyme, majoram or oregano, salt, pepper, a pinch of brown sugar - then let it all cook on a low heat for a good hour. That is a good basis for spag bol sauce (just add browned, cooked mine meat) or chilli (same with the mince but also add a spoonful of chilli powder and a square of dark chocolate) served with rice or baked potatoes, or you can just have it as a veggie sauce with pasta and grated cheese.
DH says Prue Leith's book How to Cook is the best basic one.