I ve had and am having the hardest time trying to figure out which hypothesis test to use for the following:

A 2 tailed test

Known: n = # of trials

mean for sample 1

mean for sample 2

n's are <30 AND population variances are NOT known. Since variances are not known, I should use a t-test, but then in order to get Sp^2 I need the variances. Am I trying to use the right test?