If you are interested in the environmental impact of what you eat this resource is great:
https://ourworldindata.org/environmental-impacts-of-food#you...
Note that you don't need to go vegan or vegetarian to reduce the impact, e.g. replacing any beef with pork or chicken is huge! It's way more important than cutting out milk.
If you primarily eat ground beef consider trying impossible, there are good vegan butters at this point and some okay attempts at cheese. All of those reduce the impact.
