Salesforce onsite - Full stack engineer

What is the breakdown for a Salesforce onsite interview which includes a lunch with the manager ? What kind of technical topics do I need to focus on ? What kind of behavioral questions can I expect and what is the expectation on their side ? Also, since this is a fullstack role, what kind of JavaScript do I need to be familiar with ? TC - 110k YOE - 2 years excluding 1.5 year internships Education - undergraduate degree in Computer Science