I put gas in my 2007 Chevy tahoe and it acts like it doesn't want to start, but then it will. Does anyone know why, or what I can do

Assuming there is spark at the plugs and ignition parts are working, I would check for fuel delivery to the injectors.It's cheap enough to put a new fuel filter on the vehicle if it hasn't been changed in a while.Sometimes it's simple things that keep a vehicle from starting.A fuel pressure gauge should be used to check for fuel pressure at the injectors. Also check all the electrical connections at the injectors and make sure you hear your fuel pump pressurizing by turning the key to just before starting engine.Listen for the pump.At that point you should hear it. A fuel gauge can answer alot of questions relating to the fuel system though. There are many videos online showing how to use a fuel gauge.It's like hooking up an air hose to a tire valve.Except no air is used.