Reanie, you have certainly received excellent tips here that should see you through any wine tasting. Nevertheless, I will add my 2 bits' worth for good measure.
1. When the wine is poured, just lift the glass from as low as possible from its stem (be careful in the beginning not to tip the glass over - on this account at least, the simple black dress mentioned in some posts would do just fine, less so for the table cloth, but you cannot have everything) hold it against light or a white wall as background and observe its colour (it's red of course but never mind) with as studious an expression as possible on your face. It would be of advantage to mouth such terms as deep mahogany, ruby red, etc. (Google may be of help here), but you don't have to say anything really. Just enter a note or two (the organiser of the tasting usually provides pencil and paper for this purpose) and make them as unintelligible as possible (in case someone looks over your shoulder).
2. Swirl the wine around the glass. (Careful! This may also have an impact on dress and tablecloth alike. Just watch how the others do it but do not be as exuberant as the most experienced of them). Presumably this should release the aroma of the wine for you to smell. Therefore, just as the others, put your nose into the glass as far as it can go and inhale deeply. Once again, you are lucky. Terms such as bouquet followed by any single name (or combinations thereof) of exotic fruits or even flowers (currant, pomergranate, wild cherry, ????berry, etc) are not really necessary at first. A deeply appreciative facial expression will do just fine followed by a studious entry of a couple of further notes (in the same type of handwriting mentioned earlier).
3. Now comes the real part. Take a sip of wine and a sizeable one at that (without running any undue risk of having some dribble down your chin). Do not gulp it down and do not spit it out as yet. Swirl it around your mouth without undue concern for doing in public things that your mother may have taught you that are bad table manners (look around you at the more experienced tasters to see what I mean). All this is supposed to reveal how the wine tastes on the tongue, the palate, perhaps in an ocassional tooth cavity, or other parts of your mouth (but be careful not to explore too far back for obvious reasons). Eventually do spit out the contents of your mouth into the bucket that is provided for this purpose. Notions of proper table manners still do not apply.
4. Finally, the nitty gritty. It will probably be impossible to get away at this stage with approving facial expressions, gestures, and entries in your notes only. You must say something now for sure. As advised earlier very correctly, agree with those around you, more enthusiastically so with those who have something good to say about the wines tasted. For maximum effect, you can add to their comments. The safest additions of this type are taste attributes. Just build up an inventory of exotic and hopefully obscure fruits and flowers and trot some of them out as the situation warrants. Remember again, that you are on solid ground provided that you do not disagree with anything. Thus if one detects a hint of black currant aftertaste in a certain wine, you can agree and add that there is also a faint notion of banana as well. Don't worry, it's unlikely that anyone would disagree with you either.
Have a good time!
P.S. Bonus pointer: If the wines to be tasted are old and therefore expensive ones, inevitably some of them will be well past their prime but no one will be willing to say so. Thus in the colour appreciation part, instead of saying "this wine is gone," say instead "the wine has an exquisite chocolaty tint."