I have a starting probleem - 2005 Toyota Avalon

Your not stating whether the starter is turning over or not.need more info. If starter is not turning over check the connections on your Battery are clean & put a volt meter on the battery & make sure you have close to 13 volts, if not charge or jump start the battery. If this doesn't work, have someone turn the key trying to start it, while you find the starter & give it a couple of wacks with a small hammer on the side of the starter case, if the car starts then the brushes in the starter are worn, buy a new starter, cause after wacking the starter & it starts, it might be ok for awhile, but it will happen again.

Check your battery first if it's good then check your gas level