Swinging is mostly something that couples do with other couples and most of the groups, clubs, vacations, events or cruises are geared towards committed couples.
If most swinging is between couples does that mean as a single person you cannot be part of the scene? The simple answer is its much tougher as a single person but not impossible to be a swinger as a single.
If you are a single female its generally much easier for you than a single man generally because swinging couples are more often looking for a single woman to join them than a single man. Many couples swinging groups are often more likely to allow a few single women to attend the events than single men.
If you are a single man all is not lost as often single women may want a partner to attend a couples event or some clubs will allow a select group of single men in or have single men nights. There are commercial clubs in some cities like the Red Rooster or Green Door in Las Vegas but in my experience you are more likely to see several single men standing around watching while a couple have sex although it is possible you get invited to join.
There is swinging apps and also threesome apps but in my experience you might have more luck on a threesome app talking to a couple than on a straight swinging or sex app.
If you do get invited to be with a couple or go to a mainly couples swinging event be respectful you are a guest and if you want to be invited again don’t be rude or pushy or expect anything to happen just have fun.