Motocross Photography Camera Suggestions!

Hi! My names Louisa and I'm just getting into motocross photography. I've had lots of professional opinions but I wanted to here some more people out. What I was suggested to get for a first camera is the Sony a6000. I've been searching around and its quite pricey. I would like to find a higher end camera (like said) lightly used for a deal. Does anyone know if the Nikon T6s are any good? Also whats an affordable lens? I heard the 70-200s are nice but after looking, it seems to be that they are more than I want to spend for just a camera. I need to stay under $500 for some used gear. What are some good cameras and lenses for a beginner who would like to take some decent photos? Some visuals would also be awesome! Thank you everyone in advance.