Excellent questions.
Swing clubs are social and sexual. Moreover, as a single male it is essential to remember that you are there to fulfill a couple's (or a lady's) fantasy, not the other way around.
Things that matter:
1. Perfect grooming and hygiene. From eyebrows to toenails, you want to be at least attractive to all five senses.
2. Choose clothes that are simple yet in perfect repair. Choose neither exotic nor elaborate--you are a blank canvas for others' thoughts.
3. Be rested. Avoid depressants such as alcohol. No street drugs of any kind. You may find it useful to "drink socially at the party". Very light drinks (such as a white wine 'spritzer') or not at all.
4. Smile. Let your expression and body language be open to all.
5. Choose conversational topics that are at least upbeat. Think about how you might compliment a lady on her dress, her shoes, her jewelry, whatever.
As a single male you have to strike a balance between letting people come to you and reaching out to those who seem either interested or isolated. The latter is important. It happens from time to time that the gent goes to the swinger club and does not stay close to the lady. One of your most important tasks is to spot ladies who seem not only isolated but even uncomfortable. Your greatest successes will come in making those ladies feel wonderful about the club and wanting to come back.
People who come to swinger clubs are there to fulfill fantasies. As a single male, that's your role--to help singles and couples fulfill fantasies. Have three or four ways of asking about their fantasies for the evening, and what you might do to help fulfill them. Listen carefully, and look at body language.
At some point, intimacy will be suggested. After all it is a social and sexual experience. You must learn to ask two things with clarity and with grace. The first is asking for consent. The second is asking for boundaries or limits. This will seem terribly awkward at first. With practice it will be easier.
Once you have established consent and limits, it is important to ask likes and dislikes, turn ons and turn offs. Again, it will seem awkward at first. Ask both, but especially listen to the lady. Ladies run the lifestyle.
Err on the side of safe sex. Err on the side of gentleness. Focus on her pleasure. Regardless of the experience, make sure you tell every lady or couple how wonderful the experience was for you and how they are unbelievably hot. No one goes into the fantasy with the idea they are terrible at intimacy. At the same time, if the gentleman asks you what you did to make is lady scream with pleasure, be generous with the information.
Have a plan and toiletries and extra clothes as needed to freshen up after a play session. The next couple wants you to be just as fresh.
Never, ever, "kiss and tell". What you do with one lady or two ladies or a couple or whatever the scene happens to be, it is for others to discuss and never you. Such discretion will always be appreciated. Do not ask for their names or contact information; however be generous with yours if asked. They will remember you to the club and to other members.
Above all, remember the golden rule: do unto others.
Good luck.