You can read current LSE students' views and experiences of LSE100 via the School's student blogs:
Check out this video featuring Diza, Emma, Saraansh and Adam discussing the most valuable aspects of their time studying on LSE100:
You can also check out videos about other students' experience of the course and their advice for future students here.
LSE100 is what makes doing an undergrad here so unique: you are forced to not be insular in your thinking. Insularity is perhaps the greatest enemy of knowledge, especially in social sciences.
My advice would be to view the LSE100 module as preparing you for life. You should join in the class debates presenting and defending your opinion and delve deeper into topics you found particularly interesting. When doing group projects make sure to utilize the skills that each individual has in order to have the best possible project. Moreover, make friends with your fellow classmates!