Yes, 800 numbers do use minutes from your monthly allotment (unless you have unlimited).
do you use up minutes calling a 800 number
An 800 number (or any "toll-free") will use minutes on a cell phone plan. The "toll" is referring to long-distance charges that normally apply to land lines. Most cell phone plans do not have "long-distance" or toll calls - so a toll-free number on a cell phone is meaningless.
Yes, with wireless phones a minute is a minute.