You can change your account information by going to Settings > Account Settings. Here you can change the account name, email, phone number, address, and website associated with your account.
On this page you can also change the brand colors and account description. Click the "Save" button once you have finished editing the brand colors and the description. Below the description box is an area where you can upload an account image. This image will be the default placeholder in email templates. Click "Upload Image" to upload the image and save it.