2007 Nissan Sentra = Hard to start

it takes several attempts before the car actually starts. have replaced the battery, fuses but nothings changed. i do oil change on time but they can never reset the little light. it disappears for aa day or so then reappears again. not sure what is wrong with the car

By “little light” do you mean the CEL?
First step, if you want guesses on what might help is have the codes read and post back with the actual code numbers.
Sounds like you are not using an independent shop but going to a chain store. Find a good independent shop and have the car properly diagnosed rather than throwing parts at it.

I assume the “little light” is the service reminder. My Corolla has a similar light that comes on every 5k. If the light comes back on there’s probably something else wrong. It might even be what’s causing hard starts. Have a good independent mechanic look at it.

The next time you go to start the car, turn the ignition switch on so the dash lights come on for two seconds, and turn the ignition switch off.

Repeat this a half dozen times and then try starting the engine.

If the engine starts, it points to a problem with the anti drain-back valve in the fuel pump.