You are doing the right thing gathering information prior to having it looked at.
Personally, I do the free or inexpensive things first. Have a car buddy do the inspections, inflation and if possible, throw him a 6-pack to rotate the tires. If not, a tire shop would probably charge $30 or maybe less for this service.
Lets break down the additional information:
and said it didn't line up right, and that the tire was worn on the outside part
Uneven wear is usually caused be improper alignment. And improper alignment can cause a shake in the frone end too. My car would shake like crazy under acceleration
starting about 48 MPH and continue until I let off of the gas. A $40 front wheel alignment cured this.
my friend shook the tire and it moved
Jacking up the car and shaking the wheels is done here in MA during safety inspections to check for worn ball joints, tie rods and other outer suspension components. This could be the cause of the shaking but would think that other symptoms such as a wobble while steering would be present too. Nevertheless, if you do have worn suspension parts, it would be important to get that fixed for safety reasons.