I'm not Christian, so obviously taking communion is a moot point. But if it's offered in individual cups and it holds a special significance for you, I can't see why there is any harm in having a sip. You don't have to down the whole cup if you don't want to. I had a few symbolic sips (maybe about a 1/4 of a glass) of champagne when we celebrated announcing our pregnancy to my husband's family, which I thought was no big deal. However, if you don't want to drink wine, most churches I've ever been to as well as any synagogues (I'm Jewish, we do something very much like communion in our services) always have grape juice available for children and those who can't drink, so you might want to ask if this is an option if you prefer it.