Linux Mint should be a good option. I know a co-worker used to install Linux Mint onto some of my organization's old white 2007-2010 MacBooks to give to some less fortunate people. This co-worker doesn't do a lot with Linux so it does go to show Linux Mint is not difficult to use on these older Macs.
IIRC, you may need to pull the Camera firmware file from your OS X 10.6 installation if you want to use the built-in iSight Camera in Linux. There are instructions online on where to find this file and how to use it on Linux. It has been some years since I installed Linux onto one of these early 2007-2009 MacBooks so I don't recall specifics, nor do I have a link to those instructions.
Just make sure to avoid installing Linux on the original 2006 MacBook with 32bit Core Duo CPU since that specific model has some firmware issues which could cause Linux to brick that specific model Mac. I've never had any issues using Linux on the 64bit Core 2 Duo CPU Macs (model years 2007+).
Make sure to have your OS X 10.6 Snow Leopard upgrade DVD available just in case you need it to reinstall macOS later on.
Linux can work on systems with as little as 2GB of RAM if you only use one or two open browser windows, but 3GB or better yet 4GB is best. With the MacBooks, the GPU takes up some of the system memory.