I have just decided to play guitar after having piano lessons for almost 9 years. What’s the best acoustic Guitar for about $300.00-400.00? Also any advice for a new player? Thanks.

af series ibanez artcores are excellant guitars for that budget and welcome to the world of guitars!
I would definately suggest looking into and personally playing these brands...

Art and Luthier

All have great sounding models in your price range. I just got myself a Samick OM4CE acoustic and it's absolutely amazing for $250.