What to wear: something smart that you feel comfortable in. Just make sure you are well presented, clean, tidy etc. Skirt and top, nice modest dress, smart trousers and a nice top - I’d stay away from jeans or leggings though.
Questions: things like why do you want to job, what will you bring to the role, they’re pretty standard interview questions. Have a really good think about your transferable skills, and don’t discount running a household (budgeting skills), getting the kids to schools/clubs on time (time management) kids parties (planning skills), dealing with difficult people (there is no person my difficult than a two yr old!)
No idea why they would ask for a written application, I’ve never come across that.
References - if you have no recent job references, usually you would get a character reference from someone of standing who had known you for a long time. Ask the employer, they will tell you what they need.
Will you get a job as you’ve only had one job before? Well, before I got my first job, I had never had a job before! Everyone has to start somewhere.
Combat your anxiety by being well prepared. Plan what you’re going to wear, how you’re going to get there, all those little things will help. I’ve got a job interview in a couple of weeks and I’ve got a plan stuck on the kitchen wall - it includes outfit, travel plans, remember/gather necessary ID documents, and then goes into all the technical prep I need to do (specialist office job). I’m a great believer that prior preparation prevents poor performance!
Try and keep talking, there’s nothing worse than deathly silence when you’re interviewing someone. It’s ok to show you’re nervous in the interview, and it might help you if you acknowledge it to the interviewers.
Don’t be afraid to ask them to repeat or clarify the question, and it’s perfectly fine to take a short pause to think before you answer.
Have a question prepared to ask when they ask if you have any questions - anything from shift arrangements to uniform requirements, just ask something.
Above all, just be yourself. Good luck, I hope it goes well!