I’m 15 years old, got my first client today.

Long story short, I’ve been into programming for around 4 years now I started with software development with C# and C++ and then moved to web development because I found it more fun. I opened my own sort of freelancing business which is super professional and have somehow obtained a client lol. I’m so happy about this and I’m gonna give him the best website I can physically design. He’s paying €1,500 which is great. My question is any tips on how I can bring in more? My design is great and unique and I put my heart and soul into every project.