What @paulc recommends is def good and yeah I’m assuming Java not Script based on what you said. If you’d rather spend no money this is what I would do.
Go download NetBeans unless you have a programming program you already enjoy. I like Notepad++ on windows for quick things, but NetBeans is the bees knees (yes I really did just use that term) when it comes to Java development. (Plus it’s totally cross platform so that’s a huge selling point for me since my own house is a mixed os environment)
Then start here because starting with the free stuff is always better.
You can also use this as another reference place.
Lastly, cheat sheets are really useful. I still keep my VI cheat sheet taped above my monitor. I haven’t found one quite as nice as the ones from Added Bytes for Java, but they still work.