i also mentioned that you can and should make a dedicated partition for /home :)

also, pretty much all of the distros i recommended have the option to "try" and in the live system you have Gnome Disks which is practically identical to the one in macOS

i recommend using it to slice up the disk although gparted can be better in some regards.

all distro and home partition just use ext4, don't be tempted to use btrfs, even though it's getting better you can have issues with it

also, in fact you can probably even use merely 100gb of space for each distro, rather than 200. i only recommend 200 in case you do end up wanting to install a lot of apps via dpkg or pacman or whatever