Import and Edit audio file in Garageband?

First, this is FOR iPad! — not old ipad, ipad air running ipados 17.0.3.

I have 2 .m4a audio files.

I suppose GB won’t import m4a? So first, how do I transcode them?

Second, how then do I get an empty GB “project” to import them into?

I want to trim each file first.

Then I want to put (export) them as one file with a bit of silence between them.

Somebody please save me! This was SO easy back in Quicktime Pro days! d’oh!!!

Thank you in advance.

???