You can find videos on YouTube or IG. Bubbleman and his bags (called bubblebags) are basically the standard that everyone serious uses, but there are plenty of knock offs made for alot less. I can't name any as I don't know them but you can even Google bubblebag knockoff.

I've never done it but a rough break down is.. Have the buds broken up fairly small, lots of ice and make sure your water is as cold as possible. You agitate (some use a wooden spoon, some use a drill with a paint mixer bit) the product to break the thc off of the plant, the hash (trichome heads n shit) hang out suspended in water and then you drain the water through certain bags that have a particular sized filter in the bottom which catches x. Repeat with smaller bag. Repeat with smaller bag. Then that's one run.

And you keep doing it until the material stops spitting, some people do several runs of the same material, but they are also careful not to beat the fuck out of their material and break it down so there's plant contaminant in their hash or its not as pure as possible.

Check out a guy on Instagram called @solventlessmind he does traditional bubblehash by hand every day and you can usually see him working on lives / ask questions and learn quickly. Goodluck!