Your Thinkific site can be customized from the Branding page of your admin dashboard.
Further customizations can be made using our Themes feature, but this is an option intended for use by instructors familiar with HTML/CSS only.
Whilst we're able to provide basic guidance with using Themes, we're not able to provide support in terms of working on your theme directly, or providing instructions for making significant changes.
If you're looking to significantly customize your theme, we would recommend hiring a designer - check out our list of approved web design freelancers on our Experts marketplace!
And for small changes, try searching our Help page for articles or forum posts from the community!