Hold on a sec.
Documentation on the compiler itself.
Book on Boriel Basic itself on Amazon.
ZX Basic Studio which uses Boriel Basic, also recommended by the Boriel Basic book.
Here are some links to get started. My only tip is that if you're used to Sinclair BASIC, there is a mode in the compiler and ZX Basic Studio that helps with compatibility among other things. Good luck and have fun.
PS: I should note that Boriel Basic is mainly just a compiler with extra bells and whistles and you can use it in any text editor such as VS Code and Geany.
PPS: Here's a link to Boriel Basic in the VS Code Marketplace.