You learn to sew, and start making your own designs. You wear them and see if your friends will wear them. Then hopefully people will notice and want to buy them. Then you make more and sell them.
How to be a fashion designer in a young age?
You do NOT need to know how to sew to be a fashion designer. As a fashion designer, you will be the person who does just that - design clothing. So you will sketch your ideas on paper and then help in choosing the types of fabrics to create them. After this, a pattern maker will create the pattern for your sketch. Then a seamstress will then be the one who will sew it to create what you sketched.
Depending on their level of responsibility and the company they work
for, designers may work to their own brief or be given a brief to work
towards, with specifications relating to colour, fabric and budget.
Find a job: https://www.prospects.ac.uk/job-profiles/fashion-designer
Do you dream of becoming a Fashion Designer? Fashion Designers use their knowledge of style, timing, cut, texture, fabric and current trends to create items for a commercial marketplace, in clothing, accessories, footwear or textiles.
Get a degree in fashion design. Most programs are three or four years long. Apply for an internship or apprenticeship. Best fashion designing college in India is gurukul school of design in Jaipur. You can apply here online also for query.