A lot of means a large number or quantity. In this context, it is used to describe that there are many new individuals present in the group.
Sentences with «lot of new people»
Speed dating is a fun way of meeting lots of new people in one evening. (asiand8.com)
Our speed dating nights are regularly hosted across the country and are a great way to meet lots of new people in a short space of time and find that spark! (uk.match.com)
Like a lot of our readers, I'm still getting used to newly drawn state legislative districts with lots of new people running in them. (hudsonvalleyone.com)