That is a great idea! Are you looking to create something similar to Upwork? Templates are a great launchpad when you are new to Airtable, but once you are familiar with it you will find them more of a hinderance and you will find yourself starting from a blank base more often.
While Airtable will make a great backend, you may also want to create a frontend for your users. Softr is a great place to get started as it connects to Airtable out of the box.
At a minimum you will want a few tables:
People | Company | Jobs | Skills | Platforms
All of these are related and will be linked together.
As a freelancer, one more place to put my details is only helpful if there is return on that effort. What is your service providing outside of a directory? Is there a way for potential clients to contact me? Will you manage that contact? Are you bringing potential customers to the platform? If so where/how are you generating these leads? Will customers be able to comment on my work after I have completed a job? What do I do if someone posts an incorrect statement? Are you vetting the freelancers that post their information?
All of these are thing to think about as you design your Base and what type of information you will want to store and provide access too.