I recently brought a new 5 gallon tank, new plant and a new betta at the same time.
My new betta is recovering from fin rot and stress from being shipped three days ago. But he's gotten better and he love his new home.
Very pretty boy. I know with the right care he will have his fins back and his health back in no time. The tank is very nice and you have room for a few more plants. You'll find your new boy loves plants.
Your boy looks to have been fin biting. This can happen in shipped fish. Get some SeaChem StressGuard and add daily for at least two weeks. This is what I do when this occurs and have never had further issues.