You're not going to be able to do squat for video editing or streaming on a 250-370 dollar laptop. the best laptops in that price range to be completely honest are chromebooks. Chromebooks aren't bad but you can't do much other than chrome based stuff, hence the name. If you just wanted to watch videos and could tolerate a 720p screen, chromebooks would be fine, but I will NEVER recommend any windows laptop at that price point unless for some odd reason it has more than 6 gigabytes of RAM. 6 is the bare minimum that one should accept when using Windows 10, and 8 should be the target minimum. Only get 6 gigabytes of RAM if that's the absolute best you could afford at the time. You may be better off spending a couple hundred extra dollars on something like the Acer Aspire or one of the many HP x360 models. I personally recommend the x360 over the acer simply because I've got better product history with HP than I do Acer. I personally didn't get my laptop on Amazon, couldn't find one for my budget that was good enough. I paid 400 dollars for mine. I have the HP 15-bw053od. It's a 15 inch laptop with a quad core AMD APU and pretty decent integrated graphics (good enough to game on actually) it also has 8 gigabytes of RAM out of the box but I could upgrade to 16 any time for pretty cheap. Also it has a pretty slow 5400 RPM hard drive but that could also be swapped out with an SSD down the road. Amazon may not be the best place for you to get yourself a laptop unless you wanna bump your budget up by a couple hundred dollars, I got my laptop at OfficeMax. Microcenter is also a good place to look for laptops though. Here are a couple links to okay/good laptops on Amazon, which are sadly about your 370 dollar limit:
Both of those are pretty strong for the price, but they wouldn't be the absolute best at video editing. Depending on the webcam streaming you want to do those laptops could do just fine. The acer would do video editing a bit better simply for having an SSD installed already, but if I remember correctly, you could also put an SSD in the x360, which is also a touch screen, which I think is pretty useful for a lot of windows programs outside of gaming.