As mentioned from the other posts, The recruiter will have answers to those questions. I understand you may want as much data from multiple sources to feel best prepared.
The residency program is a good way to get your feet wet in multiple roles within Google, while getting the experience you need to develop your career. You passed the phone screen which is a feat in itself!
As with all interviews, phone screens seek out potential in the candidate and if they warrant on-site interviews, need another phone screen, or end the process right there.
The questions you get on-site vs phone screen really depends on the interviewers; sometimes they're the same difficulty, sometimes they may be easier or harder depending on your strengths and weaknesses.
The challenges of an on-site interview is much heightened compared to sitting behind a phone. You have to be comfortable whiteboarding your thoughts / solutions and communicating to the interviewer effectively. It can be a sensory overload, especially if it's your first time. This sometimes is enough to trip up many candidates. Interviewers understand candidates may be nervous so it's OK to be so. They'll usually help to remove the shroud or nervousness so you can focus on demonstrating your capabilities to the fullest.
Your recruiter is your best tool to maximize your chances at getting a role at Google. They will coach you through the process and help remove the unknowns. Your success is their success. Be comfortable with asking them!
Good luck!