Hi and welcome to Knitting Help!
RS is right side of knit fabric, the side facing outward or the public side as opposed to WS, wrong side which is the side closest to the body.
KFB, knit front and back of the same stitch, an increase
w&t, wrap and turn, a way of creating short rows
SSK, slip, slip, knit slipped stitches together (slants to the left)
PFB purl front and back, an increase
PSSO, pass slip stitch over
CO, cast on
BO, bind off
There's a Glosary tab at the top of this page that defines these terms and more and has videos for many of them too.
Enjoy knitting your pattern.