Yes. You can have just a Splash Page where users have to accept your acceptable use policy, and then they get connectivity, no authentication. Or you can have a Splash Page with Active Directory authentication, or a number of other options too. You can also do sponsored guest logins using the in-built Meraki directory.
If you want to do 802.1x you can also do it using the in-built Meraki directory, so no need for a RADIUS server. This is only really good if it’s a small number of users otherwise it becomes unmanageable - but a good option nonetheless.
it all depends what you are trying to achieve as to how you would tackle it. But there’s plenty of options if you don’t want to use RADIUS.