The classic trap is thinking you need to match market prices when you're just starting out - wrong. What really matters is figuring out how much you need to charge to make it worth it for both sides. First, calculate your actual expenses (contributions, equipment, taxes, downtime between projects) and add a margin that lets you live properly. If you're doing 150 billable hours a month and you need 3500€ net, your rates have to cover that - it's math, not up for negotiation.
The thing people forget: clients looking for "cheap" are never satisfied anyway, even if you accept their terrible rates. But the ones looking for someone reliable who knows their stuff? Price isn't their main concern. So instead of dropping your rates to please everyone, target the kind of work where you're actually good. A web dev with a permanent job doesn't need to take WordPress tinkering at 15€/h to pay the bills - you can say no without worry and go after a real project at decent rates.
One concrete trick: pitch your first freelance gigs to people in your personal or professional network before jumping on platforms. They already know your value and your terms won't matter as much. It lets you test your rates on real work, build a solid portfolio and recommendations that speak for themselves. Once you've got two or three good projects under your belt with happy clients, you can post higher rates on platforms because you've got credibility to show.