You can run "license show" from the CLI.
There's also a spot in the GUI -> Cluster -> Settings -> Licenses
You can also check what shipped with it via my support.netapp.com -> Systems -> Software license
If you don't have it you can work with your Partner or NetApp account team to request a quote or trial.
And yes you can use snapmirror with snaplock, but there are a few things to know.
https://docs.netapp.com/us-en/ontap/snaplock/mirror-worm-files-task.html