How to do statistics for a lab?

I have never done statistics or lab before! So, my professor gives just a packet to do for class. 

My basic question is how do I do unpaired t-test, a paired t-test, and linear regression for descriptive statistics? I need to have the mean, mode, median, variance, standard deviation, and standard error.  I got a quick rundown of it to use on Excel... except when I tried all I got was an error sign. Is there somewhere online where I can just run the numbers through (which would be easier as it's hard to find a computer at the university)?