Make sure that your store is compliant with the law of your country. For example, in EU you must obey GDPR regulations.
Terms of Business can be added as a Page.
Go to Pages & blogs > Pages > add Page. Write a name e.g. Terms & Agreements, add the content you want and then save.
Next, you can add it to the footer. Go to: Layout > Navigation > Footer menu and add a new link. Write a name and in the URL choose Pages and look for the page with Terms & Agreements. Check if the link is properly displayed in the store.
If you can’t see it, go to Layout > Customise > Footer and choose which menu should be displayed in the respective columns in the footer.