Why does the Torah see fit to inform us that a Ger too, must bring a Korban Pesach when we do?
Rashi: Because we would otherwise have thought that he brings it when he converts. 1
To whom do the three categories "Lachem, vela'Ger ul'Ezrach ha'Aretz" refer?
Seforno: "Lachem" refers to everyone, in the Midbar; "la'Ger ul'Ezrach ha'Aretz" refers to converts and native Yisraelim in Eretz Yisrael. 1
A convert does not inherit land in Eretz Yisrael. One without land is exempt from Aliyah l'Regel. The verse teaches that even so, he is obligated in Korban Pesach. (This was inspired by Tzelach, Pesachim 3b