My personal advice about getting familiar with FreeBSD is to simply install it somewhere, play with it and get used to it. A couple of USB sticks or a spare disk in a USB enclosure can be very handy as long as you can boot your computer from USB.Unfortunately, I have none of those, all I've got FreeBSD on is my old laptop, not my main one which I'm not confident enough to install it on. As much as I don't know what I'm doing, I'd like to thing I have the logic in my head to not nuke my system or whatnot, but hey, I don't want to eat my own words lol.
I would start by installing Ventoy on some device. It needs two partitions, but you can allocate some free space as part of the install. Select GPT partitiioning.
Once you have it installed, put https://download.freebsd.org/releases/ISO-IMAGES/15.0/FreeBSD-15.0-RELEASE-amd64-bootonly.iso
on it and try and boot from it. Hopefully you will be able to get it installed on a second USB stick which you can use as a basis for getting started.