How do you track user feedback and product ideas at a very early stage?

Hi everyone - wondering how you keep track of user research and/or product ideas/roadmap at a very early stage (pre-MVP)? We are spending a lot of time talking to potential users, doing surveys, brainstorming solutions, etc. and I am trying to track everything in Airtable and it's a bit messy, but also don't really need a product management software yet.