This is the basic first step. You must choose what you would like to design and then comes the fun. Search the internet to find trends or coming trends and if you want to, go for it.
You can also search the internet for top selling products. Check places like Amazon or Zazzle to get a feel for it.
You must be patient with whatever you chose. Creating one (1) design will take a bit of time but if you stick to it you will succeed! I started with Greeting Card Universe and was there for a couple of year before I found Zazzle. Here is my My Zazzle Store. Oh, I almost forgot about the Magical Moment Boutique, also on Zazzle.
What do you want to sell? Not just apples I reckon. Pick something that gets you excited!
There is a huge volume of products to chose from so dig in.
T-Shirts: 👕 Mugs: ☕ Phone Cases: 📱Posters: 🎨Tote Bags: 👜Pillows: 🛋Stickers: 🏷 Calendars: 📆 Business Cards: 💼 Greeting Cards: 💌 Buttons/Badges: 🎖 Hats: 🎩 Magnets: 🧲 Notebooks: 📚 Aprons: 👙
These two are just samples of what is possible.
Just so you think this is all “baloney” see what Forbes Advisor has to say.