You probably are doing knit stitches so the yarn is at the back of the project. Move the yarn to the front (as if you were starting to purl) and move the stitches from the left needle to the right needle (if you are left handed from right to left). Then continue your project accordingly.
WYF means "with yarn in front"
K2 is simply knitting for two separate stitches. this is different from K2tog which means knit two together, where you treat the next two stitches as though they are one.
slip the stitch 2 times. Just slide two stitches onto the other needle and continue on with your pattern. More than likely you'll pick them up again on your next round.
C2B = Cable 2 back. C2F = Cable 2 front. Usually you will find the definitions for knitting abbreviations in the header section of your pattern. Although these two abbreviations are fairly common they are often used for different types of cable depending on the design of the garment. C2B could mean "slip the next two stitches onto a cable needle and hold at the back, knit the next two stitches on the left hand needle and then knit the two stitches on the cable needle." Or it could mean "slip the next two stitches onto a cable needle and hold at the back, knit the next stitch on the left hand needle and then knit the two stitches on the cable needle." Or it could mean "slip the next stitch onto a cable needle and hold at the back, knit the next stitch on the left hand needle and then knit the stitch on the cable needle." Your best bet is to check the pattern to find the definition used by the designer. Please note: The general accepted abbreviation C2B (Cross 2 Back) and C2F (Cross 2 Front) are generally formed using method 2 above (i.e., "slip the next two stitches onto a cable needle and hold at the back, knit the next stitch on the left hand needle and then knit the two stitches on the cable needle.").
It means to add 8 new stitches. You do this by turning needles so they are reversed, then insert right needle into stitches as if to knit, YO (Yarn Over), and pull loop through, slip loop just worked back onto left needle and repeat for required number of stitches. Remember that you do this, casting on of 8 stitches, on the next row also (the "next 2 rows" statement).
Seed stitch is also known as moss stitch. It is when you knit one purl one throughout but in the next row the purl stitches are above the knit stitches in the previous one (like a chequerboard) unlike ribbing where the knit and purl stitches stay in the same column.
Knitting can be made more elastic by using stretchy stitches such as ribbing. Ribbing is typically 1x1 or 2x2, but many other types of ribbing are possible, and many non-ribbing stitches are also stretchy. 1x1 ribbing is formed by knitting one stitch and purling the next. Repeat these two stitches to the end of the row. On following rows, "knit the knits and purl the purls." This simply means you should look at the stitch you are about to work and determine whether it looks like a knit or like a purl. Remember that a purl is simply the back side of a knit stitch. Knit stitches look like the letter "V," while purl stitches look like dashes ("-"). 2x2 ribbing is very similar to 1x1 ribbing except that you knit two stitches and purl the next two stitches. Again repeat to the end of the row, and again "knit the knits and purl the purls."
After a quick scan of the relatedlink (listed below), I am understanding that a shell of single crochet stitches means that a shell pattern can be made by knotting a single stitch, then skipping two stitches, then making 5 double crochets in the next stitch. Then you would skip the next two stitches and start another shell by one stitch, skip two, make 5 doubles, skip two stitches, and start another. And so on.
I assume you mean stocking stictch? that is knit one row, purl the next, so that you have the wavy pattern on one Garter stitch is plain knitting every row.
K-O in knitting means "Knit Over" or, in other words, pass one knit stitch over the next.
K-O in knitting means "Knit Over" or, in other words, pass one knit stitch over the next.
The dc2tog (decrease two stitches together) counts as a single stitch.
Slip one stitch (from the left needle to the right), knit the next 2 stitches together, than pass the slipped stitch over the finished K2tog stitch.