All visitors can see placed pins and profiles. Anyone with a Twitter/X account can sign in. It is $12 to place your pin and create a profile.
You can write a bio, what you're looking for (new friends, a date, or anything else. Perhaps you are a new parent looking for other new parents. Perhaps you make and sell pottery). And link to your website and other social media accounts.
Every person with a pin also has a permalink profile, like this.