Nick here from Shopify, welcome, and great questions!
You can edit the order confirmation page, just to confirm, did you mean more so how it looks and wanting to add your company logo in or was it something else? Shopify has a guide going through how to edit the notification templates which you might find useful. you can see it here. If you wanted to take it one step further, there are some apps in the Shopify App Store that can help you edit your order notification's that little bit more. I like Order Printer templates personally.
Shopify also has a guide going through all the steps for how to set up a contact us page/form here. There is also a blog from the content marketing team going through 5 steps to building the perfect contact us page here. Hopefully, this helps and answers your questions, but let me know if you have any others as you are new to the platform too!