Of course you can do anything you set your mind to but what Shes saying is will it be more work and yes it will be harder than say a 4 year old doing it but I am sure you can do it. Make sure you have good support from family Qnd friends. Good luck
To compete at a professional level? Yes, way too late.
These people who are cheering you on have good intentions but don't understand the reality. My son started at 10 and that was way too late for that. If you want to do it for fun you should but i't'd be a stretch at 13 to get anywhere, or a scholarship at a competitive university unless you have some extraordinary innate talent far beyond what the others who trained for years have. A lot of them have innate talent AND years of training.