Going vegan is essentially "Stop buying stuff" where "stuff" is meat. You should stop buying anything that pollutes a lot and/or has low value compared to alternatives: diesel cars, disposable plastic items, useless gadgets, etc.

If you still want meat in your diet, start buying less beef and more eggs or chicken. That'll be a good start. https://timeforchange.org/eat-less-meat-co2-emission-of-food