Not having clients does not mean you have nothing to show. You can create your own projects to demonstrate your skills. For example, start a blog and show its growth over time, run a small social media page, or build a sample ad campaign and explain your thinking behind it. Document your process and results, even if the numbers are small. What matters is showing that you understand how digital marketing works in practice. What do you think employers or potential clients look for most in a beginner's portfolio?