Store data on server without Database

I’m webGL engine developer (ThreeJS) in small company. We have some events in few weeks and my boss just told me that i have to make registration form as soon as possible, also one page should show names, lastnames and company of all registered members. Problem is that i’m very bad in databases and i have really small amount of time to re-learn it. How can i store registration data on Server without Database? I looked up on web and most instructions are unclear(because i’ve not worked on database before) and others are using localstorage (as far as i know its used for cacheing data)