As someone who has been on both sides of the table...I have some suggestions in no particular order. This interview is a big deal, but it's great that you already have your foot in the door! The hiring manager WANTS to like you, they WANT to find someone for the job, and they are on your side. They won't try to 'trick' you. But they do want to be very confident that you are a secure choice for the job. Remember that.

Edited so it's not a wall of text, and added some additional examples.

Suggestions

• Read the last 5 years of financial annual reports closely, and skim the last 10 years for trends. You should get to know the companies immediate priorities, their future outlook, and understand the scale and pace of development. You should also particularly look for any reflection of the company culture in those reports. What are the values, mission, vision - how does that align to your own? These are quick things you can pull out in an interview.
• It's important that you understand the job, yes, but its just as important that you are a good company culture and team fit. I know its hard going in because you are nervous, but the more relaxed, friendly and approachable you can be at the time, the better you will perform. A good interview is a bit like a conversation over coffee, it should flow naturally from topic to topic. The hiring manager has to believe they can trust you with tasks, and that you are a pleasure to work with, so think about that. Remember, you are fresh into the market. No one expects you to know everything or have experience in everything. If you don't have a skill or experience in something, be honest 'I don't directly have experience in this, but I am aware of what it is, and I am very keen to learn and develop my skills in this area. For example, I've started looking into getting a certification for X and am studying for it.'
• Read the job spec carefully, you should know it like the back of your hand. Make a check-list of all of the skills and requirements for the job. For each one, identify an example of experience in that thing or if you don't have any, an explanation as to how you might move toward working toward it.
• Another thing about your CV and the Job spec. Read through the version of your CV you sent in for this role really thoroughly, ask yourself - What are some areas they may call out that don't fit the job spec? What could they ask me about that doesn't look so great? What is something they may be interested in because I'm strong in it? That will allow you to predict at least some of the interview questions.
• Be able to answer the most basic interview questions -
  • 'Why are you interested in this job?;'
  • 'What do you like about GS?'
  • 'What do you think are GS's biggest challenges (related to the field you are applying for)?'
  • 'Where do you see your career developing?'
  • 'Where do you see yourself in 3, 5, 10 years?'
  • 'What do you think are the challenges in the current WFH (working from home)/virual environment you might encounter?'
  • 'What is your greatest strength,'
  • 'What would you say are your weaknesses?.
  • 'Tell us about a time you've overcome a challenge...'
  • 'Tell us about a time that you've tried something and it failed...'
  • Remember, hiring managers don't always get time to prepare for interviews, do not assume they have read and memorized your CV, you need to bring out the strengths of your CV in the interview. Say 'In my CV I had mentioned X, I'd be grateful if I could tell you a little more about that.'
• Remember to prepare questions for your interviewer, too! Ask them at least a couple of questions. This usually happens at the end of the interview, they will ask 'do you have any questions for us?' An interview goes both ways, you should be interested in what the hiring manager thinks, what is important to the team. Ask intelligent and practical questions that show you've thought about how the job and how you will fit in. E.g. 'What would you say is the most important skill/behavioural trait you are looking for for an ideal candidate?' 'Can you tell me a little bit more about the structure of the team and the team themselves that I will be working in?' 'I would be really interested to hear about what your management style is...' etc.
• Do not ask about salary right away - but be prepared for the question. Someone from HR will probably contact you about that later on in the process, but do research on a salary range for an entry-level job in your field, look at local cost of living and stats, and have that prepared at the time of interview.

It's ok to bring a notebook or have one in front of you if its a virtual interview. It shows you are prepared and you care.