This is a question that can be answered in a lot of different ways.
But let's start with a perfectly simple and honest answer.
No, in spite of what you might hear or read elsewhere, not everyone can succeed as a copywriter, freelance or otherwise.
If someone tells you different, they are not telling you whole truth.
If someone says, "If I did it, anyone can..." that is a tried and tested half-truth that should make you cautious.
You want truth? If you want to succeed as a freelance copywriter, you need four elements in place.
>> 1. You need some writing skills
You don't need a degree in writing. You don't even need to have done that well in writing at school. I got my lowest exam grades in English language at high school. (This probably explains my occasional grammatical howlers and frequent spelling mistakes.)
But you do need some kind of 'way with words'. You need to be able to express your thoughts and ideas. You need to be able to paint pictures with language. And you need to enjoy writing.
While you don't need any formal writing training, you do need to be able to write simply, clearly and with a little life and energy.
>> 2. You need some 'commercial empathy'
You need to like world of business. That is to say, you need to understand what makes business work. You have to understand what your clients are trying to achieve, and you must want them to succeed.
If you think business is dumb, or all business people are somehow dishonest, you'll never make it as a copywriter.
It is best if you are fascinated by business and marketing.
Myself, I am a huge fan of small business. Most of my income comes from larger companies, but I love to watch and study smaller companies. I love their inventiveness and courage of people who start them.
>> 3. You need ability to market yourself
As a freelancer you are isolated. Nobody knows who you are, where you are or what you do. One way or another, you need to get word out.
Some freelance copywriters are blessed with ability to pick up phone and cold-call for new business.
Lucky them. For myself and countless others, self-promotion is a painful, arduous business. But you have to do it.