writing opens doors, pose as an undercover journalist and you can get a free press pass to report on things like restaurants, concerts etc for any entertainment issue, or in todays digtal world, you do you tube video reviews where you v-log and monetise your endorsements.
Not that Ive done it, but plenty of singles do.
It used to be that young single women traded on their looks and sold them for modelling money. I never got into that but it was a big thing in the 90s if you had no qualifications for anything. Hence terrible 'reality' shows like Next Top Model . NOwadays its baking and cooking skills...but the restuarant and hospo industry can be cut throat.
Today the biggest thing with being single is to VALUE your education. People can get married and divorced, children leave, but if you learn skills they cant be taken away from you...with your hands and your mind (brain). God gave you these so use them.