I'm in exactly the same position. Veggie for 20 years, DH and two DCs are not and in the last year I've had to take over all cooking from DH due to changed circumstances.
I mostly stick to beef and lamb as undercooking isn't risky. Undercooking chicken and pork is, from what I understand.
Like you, I started with beef mince (cottage pie, mild chilli, mince and gravy). Have recently tried lamb mince for moussaka - needs some fat draining off after initially browning in pan, but otherwise similar to beef mince. I'm now moving on to things like lamb chops - these were surprisingly easy. Brush oil on each side and then cook 6-7 mins on each side in a griddle pan on top of the cooker. I've also cooked beef casserole (brown cubes of beef, add raw carrots, turnip, parsnip etc, add beef stock made from stock cube to cover meat and veg, stick in oven, time and oven temp on beef packet). Lots of the meat packs have the basic cooking instructions on the labels.
For fish, I've mostly done salmon, which both my DCs adore. As Hulababy says, it's easiest done in the oven. I brush foil with oil, put salmon on foil, season wrap into parcel and cook as says on pack. Recently tried cooking it on couscous with roast veg wrapped in baking parchment in oven using this recipe www.bbcgoodfood.com/recipes/1583/herby-salmon-and-couscous-parcels. Used coriander and garlic couscous, went down well. There are loads of recipes, eg on BBC Good Food site, for variations on oven cooking salmon.
Can also coat strips of white fish or fillets of plaice in seasoned flour and fry. Need a good non-stick pan for this one.
We also have good-quality sausages in various forms - with mash, in casseroles. And bacon in pasta carbonara - cook pasta, fry bacon and chop into pieces, fry finely chopped onions and mushrooms, add hot pasta, bacon and cream to frying pan with mushrooms, cook for a minute or two on low heat, turn heat off, add an egg and stir through hot food until a cooked but not too scrambled.
Hope this helps.