"You just have to work it out for yourself as you go along," he says. "I knew that I could execute food to a high standard, but that confidence leads you to assume that people will come, which isn't the case. You have to keep building your reputation and brand."
The business owner's team are both younger and older than him, which is challenging.
"I just accept that everyone has different ways of working and adapt my management style to reflect that," he says.
"Take the time to train your team and they will push themselves to be the best."
Despite the long hours and steep learning curves, Bartlett-Copeland has no regrets. "I know a lot of young people go travelling, but I'm ambitious and want to achieve things. Doing the hard work now means that I can enjoy life later."
Self-belief beats age
Patrick Clover was 23-years-old when he started his business, BLACKBX, a Wi-Fi management controller that gives venues the ability to offer free guest Wi-Fi. In return, the technology gathers raw data about those using the service, which can be used to assist with the venue's marketing.
"There's no time like the present, so if you have a good idea, run with it as soon as you can," advises Clover, now 25. "I taught myself programming while working for my previous employer. I quit my job and started the business when I was comfortable with my ability and product."
Because BLACKBX is proving popular, he's taking on responsibilities beyond his years to keep things going. "We're a team of nine, but I enjoy being the boss, because it gives me freedom to make decisions," he explains.
"But it's daunting having to manage a team and run a business," he adds. "I just want staff to feel appreciated, happy and motivated."
Some people doubted the entrepreneur, because of his age. Whenever this happened, Clover stood up for himself and his achievements, as well as those of his contemporaries. "I believe that we've created a groundbreaking [device]. Many popular products that we use today, such as Facebook, Snapchat and Instagram, were created by people in their twenties," says the businessman.
Embrace the age gap
At 23-years-old, Savannah de Savary found working for a property developer in New York very difficult, because she didn't have a lifetime of contacts upon which to call. This inspired her to found Built-ID, which enables users to discover the creators behind various buildings.
Despite being younger than a some of her employees, de Savary doesn't feel that her age is a barrier.
"Thanks to the prominence of successful young entrepreneurs, such as [Facebook founder] Mark Zuckerberg, people rarely comment on my age," she explains.
Age differences can actually be learning opportunities. "Some of my seven employees are significantly older and more experienced than me, but I always emphasise how I want to learn from their experiences," she adds.