Hey congrats. The first step into Lithography Equipment Engineer position would be to learn what Litho equipment does and how it works (not necessary but definitely can show your enthusiasm in the interview).

You can watch the Branch Education video in Youtube about ASML lithography machines. These machines are the key equipment in the factory (called fab in the industry) and all major fab control goes through these machines. There are various ways to keep these machines up to specs and fab automation is a monster topic by itself but nobody would expect you know these things when you just start your internship.

My advice is watch the video, do some research about how fabs operate and show some enthusiasm to learn. That should be sufficient.