I'd advise you start slow and simple and practice a lot!
What can you cook at the moment to give us an idea of your skill level? Is it still more freezer to oven things (fish fingers and oven chips type thing) or a bit more advanced?
Any dietary needs or preferences in the family!
I'm veggie and have been all my adult life so while I'm a pretty competent and confident cook and baker of veggie food I had to learn to cook meat when married and for dd (I didn't want to decide for her) and I worried a lot I was doing it wrong and about food poisoning etc and still tend to overcook it I think.
Start with basics:
How to peel and prep fruit and veg
How to select cuts of meat and fish (ask butcher/fishmonger to do any difficult prep. They're generally very helpful and have the tools which many of us don't at home)
How to make soups/stews/casseroles - these are VERY simple and very flexible/forgiving yet can seem like you've done a lot of work. I made a casserole yesterday takes no time at all to prep it's the cooking time that takes a long time and that allows the flavours to develop
Don't be afraid or ashamed to use shortcuts - lazy garlic, frozen diced onion, tinned tomatoes, fresh pasta (tonight's dinner here), ready prepped veggies are all perfectly acceptable. Even the ready made sauces aren't as bad as made out on mn - or at least until you learnt to make your own.
BBC good food is an excellent site for recipes, you can even look up by ingredient and filter by how easy the recipe is.
Learn what the various terms mean. Make good use of YouTube and watch cookery shows - even masterchef professionals can give ideas for simple tricks to use (professional chefs save time wherever they can! Without skimping on quality of food) and the voiceovers often explain things. I've been binge watching ready steady cook lately - that's super simple as they only have 10/20 mins to do it!
Build it up gradually - don't be trying a new recipe every day for a week! I read a tip somewhere that one new recipe a week is enough as otherwise you get overwhelmed and give up.
Don't worry about errors/disasters they happen! Learn from it and adjust next time you make the recipe. I made a horrifically thick scotch broth my first attempt you could cement bricks with it! I now make a lovely pot of broth now I understand better how to use Pearl barley 
Nadiya Hussain is amazing! Agreed. Jamie Oliver too for writing recipes simply as is delia
I keep a "folder" in my notes app of links to favourite recipes or ones I want to try.
Mushroom stroganoff is a favourite and I've done it so often now I barely need to glance at the recipe.
I agree for dinner parties dishes that can be served "family style" with guests serving themselves. I'm not a fan of curry/chilli these days myself when others have cooked as I can't eat spicy food any more, but stews (of which stroganoff is one I've found that can be popular), casseroles, and similar work well, can be prepped well in advance (indeed this often makes them taste better) serve with any number of carb choices (potatoes, rice, Cous Cous, pasta, even just "naice" bread rolls or artisan bread you've bought in) and veggies and salads and you're unlikely to get complaints! Salads or soup as starters can be made in advance, soup is really easy and can be made weeks in advance, frozen and reheated on the day no problem. Choose a make ahead dessert too and then all the prep you have to do on the evening is minimal.
Easy desserts - Eton mess, cheesecake served with fresh fruit, cranachan (sounds fancy, super easy!), hell get in posh ice cream and some accompaniments (the nice fan wafers, chocolate dipped wafers, nougat and oyster ones, sprinkles - go mad! Or brandy snap baskets to serve in with a simple strawberry and mint garnish)
I would say the absolute easiest thing to learn that's "proper cooking" is a good tomato pasta sauce from scratch (I say from scratch I use tinned toms) - you'll never go back to oversweet but otherwise flavourless dolmio type sauces!