The first clause supplies either the step before enjoying or the reason for it, and 즐기다 is to enjoy or make the most of something. Several of these lines are invitations from a host or a public announcement: come and enjoy, come with your children and enjoy, an app so anyone can come out and enjoy themselves. Others use the causal side instead, such as being too worn out to enjoy anything, or doing it because you like it.
Register: often a polite invitation or announcement