Welcome to the community, @Pam_Siebert!
You can turn off the toolbars, but you cannot make any further design changes.
For further design functionality, you would need to pay for a 3rd-party portal embedding app such as MiniExtensions.com, GlideApps.com, Softr.io, Noloco.io, and Pory.io.
If you need help setting any of these up & you have a budget to hire an expert Airtable consultant, please feel free to contact me through my Airtable consulting website, ScottWorld
However, your best bet might be to work with a web developer. Perhaps you are already working with a web developer! If so, your web developer could create custom code for your website that communicates with Airtable through its API, and that developer can design it in any way that you would like.