My views and thoughts are coming from times spent in clubs in the past and knowing many girls who've worked as exotic dancers. I have done amateur nights before I discovered pole, but have never worked in a club. However, these days I do get opportunity to perform with as much or as little clothing as I like for all kinds of folks every few weeks so here in SF so are my thoughts.
First, not all strip clubs are the same, I would say it's important to check out the club you plan on working in. See what the patrons are like, watch how the girls are treated by the staff too, different clubs attract different type of people. Most girls will even sit down and talk with you, at least that's been the case when I use to go. Usually (not always) you get the job by doing amateur night which can give you a look into how things are run before you work there. Remember in many (not all) clubs you don't get a ton of stage time, most money is made hustling for private dances.
Now to answer your old man question, lol what is a gross old man? Are you just referring to someone who's older and there for is seen as creepy because they enjoy looking at women? Just because someone isn't 23 and enjoys looking at women doesn't make them creepy. If they come in with poor hygiene or shout rude things, try and grab at you, that's creepy and rude regardless of age! There are good and bad customers in every industry, you know those people who give you a bad vibe) but realize that many people who enjoy exotic entertainment are not creepy, or bad people they just enjoy the tease. Too often we place anything related to sexuality as gross, dirty or secret but sexuality is healthy and a normal part of everyones life!
I will add, think about why you want to dance in a club, if it's because you enjoy the pleasure of the tease, and you love movement and flirting, the go for it. If you're wanting lot of money fast or want to feel better about yourself, not a good idea! Don't ever put yourself in a sexual situation you're not comfortable with!