To start SEO freelancing, you will need to:

1. Develop your SEO skills. This includes learning about the different aspects of SEO, such as keyword research, on-page optimization, and link building. There are many online resources and courses available to help you learn SEO.
2. Build a portfolio. Once you have developed some SEO skills, you need to build a portfolio of your work. This could include personal projects, contributions to open source projects, or freelance work that you have done for clients.
3. Market your services. Once you have a portfolio, you need to start marketing your services to potential clients. You can do this online through platforms like Upwork and Fiverr, or offline through networking and word-of-mouth.
4. Deliver high-quality results. When you do get clients, it is important to deliver high-quality results. This means meeting their expectations and helping them to achieve their SEO goals.