Let me start off saying that I would probably describe myself as a pretty beginner skier. I used to snowboard a lot growing up, but now in my early 20s have switched to skiing and have gone 5 times this winter. That is the extent of my skiing experience. At this point I am basically self taught, save for what I have read and seen on the internet...and I can get down the hill without falling. I have a keen interest in learning more, and would like to take a few lessons so I can actually learn proper technique. I have some confidence/fear issues about going too fast while I am skiing, and have had bouts where I feel out of control. Also, the last time I went skiing (I always use rentals as I don't have my own skis), my legs hurt me so badly after only a few runs that I had to stop. So I think I must be pretty out of shape? It was a way bigger hill than what I had been skiing previously, much longer runs...so that may have contributed?
Anyway, I guess that's just a bit of background info. I'm really seeking some advice here, as I recently found out that I won a pair of skis, the skis being a pair of women's 2015 Rossignol Savory 7's (http://www.rossignol.com/CG/CA/savory-7--2014--RADQI01--product--alpine-women-skis.html). I am a little bit intimidated, as the ski is described as being for "intermediate to expert" skiers, and a mainly powder ski. My immediate reaction is that I should probably sell them and buy something more suited to my ability, but I am wondering...would it be detrimental to my skiing to keep them? Would this ski be impossible for me to ski and learn on? Would they be something I could potentially "grow into"? What makes it a "powder" ski...would that be bad for mostly groomed runs? I am wondering how it is for beginner/intermediates skiing on "expert" skis. I can deduce from my limited knowledge that these are pretty good quality skis (at least I think), so would it be worth it for me to just keep them and learn to ski them? Another thing I am unsure of is what ski length I should be using...the rental shops so far have given me lengths ranging from 151-160, and I have generally felt more comfortable and stable in the shorter lighter feeling skis. The skis I won are 162cm in length. Would they be too long? I am 5'7 and about 175lbs. Sorry for all the questions, I'm just really new to all this and am seeking some advice. Any recommendations on what kind of skis I should buy if I end up selling these would be appreciated also.