I am a person who actually enjoys cooking and baking but am completely self taught.
For baking, I do use my Kitchen Aid mixer several times a week - 1) for making sourdough bagels (impossible to hand knead this dough due to the relatively low amount of hydration), and it really does make a difference for cakes and icings. I have had this mixer for over 10 years with no issues, and can see having it for 10 more. I also have an ice cream making and pasta attachments which are very handy. I think it is money well spent. Also handy is a second bowl.
I also have a food processor with multiple sized bowls. I use the small bowls to whizz up sauces (pesto, salsa verde, romesco, chimmichuri), and the large bowl for slicing potatoes for dauphinoise and gratins, grating carrots and other veg, and chopping large amounts of veg for batch cooking things like bolognese. I use this less than my mixer, but it still is essential for the sauces.
For baking, I would get heavy duty pans and baking tins - they will last, heat evenly for better results, and won't warp over time. A half sheet pan, loaf pan, and 3 high sided 8 inch cake tins will carry though most baking projects. Also helpful is a Silpat sheet, and loaf tin liners (I've had the same packet for 10 years). Essential is a good quality electric scale,
For tips, I find Youtube to be better than books because the visual cues essential to baking are better conveyed through video. Best are BraveTart videos on the Serious Eats web site, Sally's Baking addiction, Joy of Baking, and many others.
Seconday gadgets, but ones I use multiple times a week are:
- a powerful blender. I use mine for making homemade Nutella, soups, smoothies, crepe batter, milkshakes, homemade frappuchinos
- a pressure cooker. I have a Sage Multi cook and use it to make rice, risotto, anything require long cooking times (braised lamb shanks, short ribs, stocks, stews) and it makes the best risottos with no faff. Also makes fantastic rice pudding in only 14 minutes.
Also essential are good knives, a knife sharpener, silicon spatulas and spoons, and an offset spatula.