Do I qualify for the 72 transit visa

You need to change your flight first. Immigration will only issue the 144-hour entry permit if your scheduled layover is over 24 hours, and if it's shorter for any reason, you'll end up with a 24-hour permit. Overstaying your permit without a good reason will result in a 5-year ban from using visa-free transit.

I have changed my ticket, arrive Shanghai 7:30 pm on April 29th depart Shanghai May 1 at 5:10 pm, so not even 48 hrs, are there specific lineups to go into when needing the transit visa or do you just get it from the person at the usual immigration lineup....Also why would I get a 144 hour visa and not the 72 hour visa?

First of all, it's not a visa and it's called "visa-free transit" meaning that you do NOT need a visa. The permit itself is not a visa because you do not have to pay for it. Secondly, the immigration office stopped issuing the 72-hour permit two years ago, so all that's available now are 24 hours and 144 hours. When reaching immigration, go to the dedicated line for visa-free transit which will be clearly indicated and fill out the paperwork. You'll be asked for proof of accommodation in Shanghai and a phone number of that accommodation.