I would like to know if the wine is included during the meals (lunch and dinner), or if I will have to pay additional to drink wine with my meal on a Carnival cruise?

You will have to pay extra. It is not included.

You will have to pay extra for soda also.

You will also have to pay extra for bottled water. Prices on Carnival are low because almost everything besides your stateroom and meals in the regular dining room costs extra.

Winner is exaggerating a tiny bit. Food on deck, at the buffets, and via (24 hour) room service is free. There are a number of wine selections between $20-$30/bottle on the menu--actually a pretty decent variety.

Actually, wine costs extra on all cruise lines. On the high end lines you just don't get a bill for it because you paid more for the cruise and they include it at no extra charge.
Carnival does not include it in your ticket so they charge you extra each time you order it.
When you see posters say they cruise with "XYZ" line because they do not charge them for these extras they really are paying for them, just up front.
Many budget minded people like paying less for their cruises on lines like Carnival(and thats OK), especially if they don't drink and don't want to pay for this extra.