How can I get better FM reception in my 2001 Avao with a pioneer car stereo?
Add a better antenna. That will take some drilling but it isn’t all that tough.
Also, you may have to accept that the radio you bought isn’t very good and won’t have very good FM reception.
You could try something like this. At least there is no drilling. This is NOT a recommendation just something to think about.
https://www.amazon.com/Stereo-Antenna-Signal-Booster-Amplifier/dp/B00820VJCI