There's sort of only one stitch in knitting - the back of a knit stitch is a purl, the back of a purl is a knit. They're made differently depending on which side you work from. You won't see a difference in the stitches until you alternate a row of knits with a row of purls and that will make stockinette stitch. Or ribbing which is mixing knit and purl stitches on the same row.
The right tension for you comes with practice and even if it's a little off at first, when you wash the items, the stitches will even out a lot.
sue- knitting heretic