It's normal to be nervous for an interview but try and remember it's also an opportunity for you to find out more about them/the company and if you would like to work there...having that mindset helps me sometimes, it takes a bit of pressure off. Other than that:
-do your research into the company (like you already are doing) - what are the company values/strategy and how can you evidence you would fit in?
-go on something like reed.com and look at the competency-based questions, print them off and have a practice (those ones like 'describe a time when you did xyz' - if you don't have actual examples, just say so but say 'if I was faced with that situation I'd do this...'
-never lie on your cv or in the actual interview
-it's fine to say 'let me think about that for a minute' rather than rush into an answer that you aren't sure about
-prepare some good questions for them beyond the 'what is the training plan like?' (things like 'if I was successful, what could I do to make an impact here/what are you looking for in a candidate/what are the best and worst things about the job?')
-prepare for the curveball questions! Things like 'if you were an animal, what would you be?' or 'sell me this pen'. To be honest, I've never been asked these or asked them myself but you never know and remember it's just a test to see how you handle yourself, not the answer that counts!
Above all, be confident in your abilities, smile and make eye contact and if you can, chat to them on the way to the room to put yourself at ease. Interviewers are usually looking at how people conduct themselves and visualising how they could fit into their team so if you come across as approachable, friendly and enthusiastic it always goes down well. Depending on the job you are going for (and if the interviewers seem friendly!), you could say something at the start like 'it's been a while so apologies if I'm a little rusty on my interview technique hahaha' - in most cases they will rush to reassure you!
As an interviewer myself, I always try to make people feel relaxed at the start as I'd rather find out as much about them to see if they are the right person for the job, I'm not judging them on their nerves but when they are obviously terrified, unfortunately it just means they wouldn't be right if you see what I mean. So just pretend to be confident even if you don't feel it!
Oh and eat beforehand! Don't want a rumbly stomach halfway through!
Good luck! x