If you plan on streaming (which is CPU heavy), go with AMD Ryzen 7 or Intel i7 (or higher). Some folks will say a Ryzen 5 or i5 is good enough, but I have difficulties with it. If prices are too high, you can also look at last generation. Intel will be the 9000 series and AMD will be the 3000 series.
Stock cooling generally (or used to) means air and heat sink cooling. This type of cooling is not recommended for folks who plan on overclocking their CPU/GPU. Based on your response, I'd say stay away from overclocking until you're more familiar and ready with the subject. Go with a traditional air and heat sink cooling.
Go with 16GB RAM and search for the cheapest brand and model based on your motherboard compatibility list. Each motherboard should have a list of compatible RAM that you can copy-paste onto a search.
When looking for a motherboard and since you don't care for WiFi, try to find one without built-in WiFi. It'll save you some money, like $30-$50 USD.