To some extent, almost all freelancing services are free to use. This means it is possible for the new freelancers to be using them without any hinderance at all. What you need is just making sure that you have what it takes to work on all these platforms. However, there is a tendency that the platforms may charge you for using the platforms. For instance, Fiverr and Upwork do charge the freelancers for making use of their platforms to get clients.