Incorrect and inconsistent links in the Get Prepped for the Adobe Experience Manager Sites Business Practitioner Expert certification

Issue in ./help/certifications/aem/aem-sites-e-business.md
The Get prepped section contains links that are not appropriate and relevant for the Adobe Experience Manager Sites Business Practitioner Expert certification.
Below are some examples:
Under Section 1:
- [Learn about AEM 6.5 capabilities](https://experienceleague.adobe.com/docs/experience-manager-65/user-guide/troubleshooting/learn.html?lang=en) takes a user to the troubleshooting section
- [First steps for authors](https://experienceleague.adobe.com/docs/experience-manager-64/authoring/essentials/first-steps.html?lang=en) takes a user to AEM 6.4 instead of 6.5
- [Content editing best practices](https://experienceleague.adobe.com/docs/campaign-classic/using/designing-content/editing-html-content/content-editing-best-practices.html?lang=en) takes a user to Adobe Campaign Classic documentation

Open help/certifications/aem/aem-sites-e-business.md and review every link in the Get prepped section, starting with the Section 1 examples listed in the issue. Replace links that lead to troubleshooting, AEM 6.4, or Adobe Campaign Classic content with relevant certification resources; done means the section's links are appropriate and consistent.

Written by the indexing model from the issue text.