1997 Nissan Sentra Car will not start

Hello, I have had my Nissen Sentra since 1998, and this year has been the mother of all repairs and replacements. This year, here is my repair list:
1. A/C Belt Replacement
2. Transmission Flush
3. Oil Pan Gasket/Press Switch/Trans Filter/Fuel Filter/Distributor Cap/Distributor Rotor/Valve Cover gasket/Spark Plugs
4. Radiator Replacement
5. Oil Change x 3
6. New Battery
7. Radiator Hoses
8. Remanufactured Alternator
9. Fuel System Cleaning-Induction Cleaning, Throttle Plate Cleaning, Replaced Fuel filter (again), Set timing and adjusted idle speed
10. Remanufactured Starter

Okay, I have zero knowledge with cars. I actually just noticed that numerous things were done this year that were the same (spark plugs, fuel filter, etc.). I was out of town for a week for a vacation and the temperatures has been between 20-60 degrees. I returned home yesterday and started the car without problem, drove it about 5 miles to the grocery store and filled up with gasoline. I got into the car today and it started, I immediately put it into reverse and it stalled. It would not crank back up. It sounds like its flooded, like it wants to start, just does not get enough gas. I let it sit for an hour and it just keep dragging on ignition attempts. My concern is that I am going to get ripped off as I have taken this car to Pep Boys, Cottman, Goodyear, and a local mechanic this year alone not really trusting/beleiving one spot/person. It is currently at Pep Boys as that is where my insurance would tow the car (closest). Thoughts? The tow guy mentioned that it may be the timing belt, however, I'm learning that the 1997 Sentra has a chain. Anything helpful for me to ask Pep Boys to check would be very good. I'm going to ask them for all the old parts anyway.