Future Intern Concerns

Hi guys, enjoyed reading the discussions here for the past few months, thanks for many insights.

I will be starting an off-cycle internship in a BB and to be honest, I'm a bit nervous about how I'll preform, so I could use some advice. First, do you recommend taking online Power Point/Excel courses to sharp my (very basic) technical skills? What would you say are the most crucial technical skills to come with to the job? Second, I could really use advice on any other skills you feel are important to succeed on the job? My wish is of course to receive an offer in the end of my internship.

Maybe it is important to add, I don't have any banking experience...

Thanks in advance for any insights!!