Formats are less important. Phones record in m4a to chime with mp4 video. I convert to mp3 anyway, free conversion software abounds. mp3 will be around for many many years because it is embedded in HTML5 browsers, worth noting for publishing on the internet. Unless you are selling the results and even if you are, mp3 is more than adequate - the format is everywhere.

Audacity will import mp3 natively and with the Lame encoder exports happily. Editing is essential because if you are trying to catch the moment you will have far more audio that is needed for the job in hand.

Which reminds me - the Zoom H2N can be set to recorder 2 seconds before you decide to hit record - how's that a mind reading recorder! Maybe it is 5 seconds, maybe there are recorders with bigger pre-record lengths but can they do shotgun microphone emulation ? ie narrow spacial sensitivity.

Report back with your choice. Maybe there will be more questions, the Mudcat advice is a wonder, especially with audio - it is what we do!