I'll list the statistics-related topics from my basic econometrics course.
- Expected value, mean, variance and covariance as well as conditional expectation and conditional variance.
- Basic probability and probability density functions (I'd suggest getting somewhat familiar at least with Normal, Student's T, and F distribution and maybe Bernoulli, Chi-Square and Poisson) and what random variables mean.
- The central limit theorem (closely related with PDFs).
- Correlation. Also understanding why correlation does not imply causation is useful, but you'll probably discuss this in class.
- Methods of regression/estimation. You'll probably be introduced to Ordinary Least Squares early on and a basic understanding of what regression models are for might be useful although probably not assumed.
- Statistical hypothesis testing. This will probably be a main subject in any applied econometrics course, so you might take a sneak peek on the basics.
You might have to understand some matrix and equation algebra depending on how theoretical the lecturer makes the course, but these were probably included in your calculus course.