Welcome to the site, there are many practitioner's whose families do not/would not support the idea of magical practice, I am sure you will find many with wise counsel. Also adding to your doubt, 'Blessed be' is a normal farwell, or salute used by wiccans and pagans, though I do not see why any other practitioner or religious member cannot use the same term to send good wishes to all. It is not obligatory to end with a blessing, it really is up to you.
Now my question, is what do you mean by a spell to conjure mountain dew? If you are looking for a spell that will make the drink magically appear infront of you, then you must know that these things aren't possible. Now if you are looking for a spell that can attract a mountain dew drink to you in time, it might be possible. But personally I consider this would be a waste of energy, and time; since most spells need certain things in order to work. A need (a great one) is normally a great booster, and I don't think a mountain dew is a 'need' rather more of a 'want'. Tons of luck.