Without FileVault, you can totally still access the laptop and data. Sadly Macs do not have anywhere near the device protection that iPhones do - even the new ones. But data encryption is what you need.
You can do that same in the installer for Ubuntu Linux. I personally prefer the encrypt home directory option over the full disk option, but there are trade-offs.
Does that protect your computer if it's asleep? My guess is most Macbooks are either asleep or on 99% of the time.
$ sudo pmset -a destroyfvkeyonstandby 1
$ sudo pmset -a hibernatemode 25
$ sudo pmset -a powernap 0
$ sudo pmset -a standby 0
$ sudo pmset -a standbydelay 0
$ sudo pmset -a autopoweroff 0
[1] https://github.com/drduh/macOS-Security-and-Privacy-Guide#fu...