Some would-be freelancers fear that they don't have quite the right strengths and qualities to freelance ... but you might be looking at things the wrong way.
As a freelancer, you don't need to be an amazingly good writer. You certainly need to be able to write competently and fluently in whatever language you'll be freelancing in ... but you don't need to be able to craft award-winning prose.
Freelancers write all sorts of things that are, frankly, pretty mundane. I've written a bunch of posts for clients who wanted round-ups of top products from Amazon, for instance, where I simply had to go through the product description and reviews and write about the features, pros, and cons of each.
If you know that you struggle with the finer points of grammar, if your spelling isn't as good as you'd like it to be, or if you tend to be a bit wordy -- then there are plenty of apps out there that can help, like Grammarly and ProWritingAid. While they're not a replacement for a good editor, these will catch most mistakes and will pull you up on wordy or poor phrasing.
So what do you need to be a freelance writer, then, beyond the ability to write competently?
You need the following, all of which you can work on developing if you feel you're not quite there yet:
#1: Good Time Management Skills
As a freelance, you'll have deadlines. It's pretty rare to come across a freelancing gig where the client says they're happy for you to just turn it in whenever. (And even if that is the case, they're going to want it within a reasonable time span!)
You need to be able to sit down, focus, and write. If that's currently a struggle for you, I can reassure you that when someone's offering you money to do so, it does become a bit easier to get going! But if you struggle a lot with procrastination, or if you're terrible at meeting deadlines, then you'll want to work on these skill before diving into a freelancing career.
#2: Good Communication and Client Management Skills
This is something you can learn, to a large degree, on the job ... but life will definitely be easier as a freelancer if you're good at communicating clearly with clients. Make sure you understand exactly what they're expecting from you, and make sure they understand exactly what they'll be getting from you and when.
You may well need to be adaptable to how your client prefers to communicate. Most of mine are happy with emails for everything, but a couple use Trello to manage projects, and a third uses Slack.
#3: A Reasonable Degree of Self-Confidence
I know that self-confidence can be a really tricky area for writers. The good news is that getting paid for your writing can really boost your confidence! Sometimes, the best thing you can do to start with is to try to act confidently, even if you're feeling a bit shaky inside.
(If I'm 100% honest, I still don't always feel confident, especially when I'm pitching for a new freelancing gig, or tackling a new type of freelance writing. But the more I keep going forward, the easier it gets.)
All of these skills -- plus the ability to write fluently -- are ones you can develop. For more on each, plus some tips on improving them, check out my post The Four Essential Qualities You Need for Freelance Writing Success (and How to Develop Them):