Many interviewers will ask why exactly you want the position. It’s great if you have a genuine motivation to do the work that you can share with them. If it’s something more simple like financial need, etc. then it can be good to mention things like the employer being good to work for or something similar that shows a knowledge of the employer or position, rather than seeming uninterested in the specifics. Do some research on your potential employer and look out for what might be a good fit for you, as that’ll be good to mention.
In any position where you’ll be working with others, employers will want to know how much of a team player you are and how you handle working under someone else’s direction. You should emphasise your strengths both working with others and alone, since employers value both. Try to come across as able to work well with others but competent working alone.
Employers will always want to know about your prior experiences of the job. Try and highlight the best aspects of your previous work like any particular achievements you have. If you don’t have any prior experience then try and relate your work to something similar that you’ve done in your life, but keep it relevant to the role.
In your interview you may be asked whether you’ve used a particular kind of equipment or carried out a specific duty a school caretaker might deal with before in order for your interviewer to gauge how well you’d handle certain tasks. If you have little experience then read up on the kinds of duties you’ll be expected to perform in detail so you can at least respond with what you would or should do.