If you've submitted a quote but haven't heard anything from the customer, it's always worth sending a follow up message a day or so later. Everyone gets busy from time to time, so a customer simply might not have had a chance to respond to you.
It's worth asking the customer if they need any more information from you, or if there was anything in your quote that they had questions about. They'll likely appreciate the follow up and will get in touch with you.
To do this, go to 'My quotes', click on a quote, then click the 'Message' button.
If the customer has seen your quote, you'll see the word 'Read' underneath the 'Message' button in both your quote list, and in the quote details.