Will planting a non-native food crop in my backyard hurt the ecosystem any more than the non-native grass already has?

I want to get into gardening but I also want to make sure I don’t cause any net harm on the environment by starting out.

I’m thinking of just starting with a single tomato plant.

No permaculture yet because that’s too difficult. The reason I came to this subreddit is because I trust that you guys know the most about sustainable growing in general, and can tell me if I should start with a different plant.