See below

Ice blonde wrote:

Can you experience pressure problems in your ears similar to on a
commercial jet?


Yes but only in a high performance airplane, not likely for a
introductory flight.

Is it best to go alone with just the instructor, or take a willing
victim to witness your trial?


Ask the instructor if it is ok with them. If you feel more comfortable
with an experienced observer then do it.

Do they have sick bags?


bring your own. Do not use a clear ziplock bag.

Do you get a parachute in case anything goes wrong?


Only if you are doing aerobatics.

And how addictive is flying really, I mean if I open my eyes and like
it?


It is the most expensive and enjoyable habit I have. I finally am
getting paid to fly.

Michelle