When you first create an account on Stitch, you'll see a wide variety of events and activities, both in-person and virtual, for you to join.
If you choose to support the community by becoming a Full member of Stitch, you'll be able to attend any event you see listed, as well as suggest activities of your own.
If you are a Limited member of Stitch, on the other hand, you'll see that many of the events are shown with a lock symbol, as shown below:
The lock symbol means the event is for Full members only, and you will need to become a Full member if you wish to attend.
Most events on Stitch are for Full members only. Stitch is a community-run organization, built by members for members, so it stands to reason that most of the access to the community is reserved for Full members.
The community does, however, make an exception for new members of Stitch, as a way to welcome new members to the community and help introduce them to what Stitch is all about.