Best tip I ever had was "if you can read you can cook". Admittedly it didn't mean quality all the time, but worked to get me over the 'but is should be perfect first time' mentality that stopped me from keeping on trying.
Basically, find some recipes you like and then practice - they mightn't be perfect first to but you'll get there. Elizabeth David is a good one to start with. Never had a failure with any of her recipes.
For something simple I tend to do one of the below:
Spaghetti Marco Polo Cook spaghetti by chucking relevant amount (c. 75g per person) into saucepan of boiling water with dash of oil in, bring back to boil and then turn off heat. Takes 10 - 12 mins to cook depending how chewy you like it. Serve up, having tossed in olive oil. Put out bowls of grated cheese (pref. Emmenthal or Gruyere, but cheddar will do), chopped walnuts, olives, chopped spring onions, tuna fish and tell people to help themselves.
Pasta/couscous/bulgar with boiled eggs and tomato sauce. Cook pasta as above or couscous/bulgar as per instructions on pack. Make up sauce (preferably the day before) by: finely slicing two cloves of garlic and one onion, add to pan with one tin of tomato puree and one tin of chopped tomatoes along with a good pinch each of basil, oregano and marjoram (if you can get it). Add some ground pepper and a slug of olive oil. Simmer for half an hour. Hard boil suitable number of eggs (boiling for five mins will do). Shell. Serve up with carbs, sauce and green salad/other steamed veg.
Google recipes for your fav foods and compare them in your head pick and choose what you think sounds tasty.
Menu plan to avoid wastage
Ie one of my fav combos is Spag Bol Mac cheese Lasagne (with the Bol and cheese sauce and lasagne sheets)
Another is Slow cooked lamb, mash and peas Shepherds pie (combine all leftover including gravy!)
My best cooking tip is as above. Don't expect it to be look like the picture and don't give up because its not perfect.
I absolutely love cooking, it's a real passion for me and has been for years. I still screw up monumentally sometimes. Yesterday I wasted 3 basil plants, 1/4 bottle of oil, a half block of expensive hard cheese and a handful of ground almonds by adding really off garlic oil to my pesto. Expensive and devastating but what can you do, it happens