I’m not going to tell you exactly what to write, but you could say something on the lines of:
Hello. I’m _____. I can design this logo for your e-commerce business. For this logo package, I charge _____ along with a delivery time of ____. Also, I have plenty of experience making logos and I can provide some examples of my previous work. I’ve included a few extras in this offer such as ______. If you have any questions, I’m always available to answer them. Thank you.
You don’t have to write something exactly like that, but that was just a quick example that I came up with.
Also, I would recommend doing some research on the Forum and learning about what buyers like to see in a buyer request. Hope this helps!