"A tram comes from Kati and from Péter too."
Translation:Katitól és Pétertől is jön villamos.
You want to meet up with some friends in the city and ask your friend how the others are planning to come. She replies "There's a tram coming from Kati, and from Péter as well, so they are probably going to come with those."
By the way, the Hungarian sentence doesn't imply that it's the same tram that comes from both Kati's and Péter's places, but rather that there are tram lines going from their places to the meeting point (where you are).
The correct English translation would be "A tram comes from Kati's and Péter's too."
Your sentence is saying that, beside other things, also trams come from Kati and Péter. I'm not sure the English sentence contains that meaning. It seem to clearly be about "from Kati and also from Péter".
Also it's Pétertől. Follow the vowel harmony.