I don't think there's a way to migrate from AppleWorks. One stumbling block would be finding a machine that could run both AW and FMP 12. There is no such machine. If AW is capable of exporting the data in a format that can be imported by FMP then you may be able to design a db in FMP and import the data.
I can still run AppleWorks 6, with OS 10.6.8. There is an option in Save As… to use ASCII Text, with produces tabbed text. I don't know about what happens if you have other fancy stuff in the data.
Tabbed text will work. You can export to tabbed text and then import this data as a tab file Into fileMaker. What you do with the data once you pull it into FileMaker will be up to you.
Years ago, I migrated a DB created in MS Works (on a Macintosh SE/Classic) from AppleWorks (long before the 'new' AppleWorks...) to FileMaker Pro 2 (-:
I ended up in re-writing, but the data could be easily transferred via textfiles (tab delimitted AFAIK) into the new DB. I did quite some 'readings' to get familiar with FileMaker - but I was very happy and I could do a lot more with the data!
AppleWorks and AppleWorks6 was not that bad! One thing You'll miss will be the TextEditor. FileMaker doesn't have a text-system (compared to AW, 4D, RagTime et all). But in every other aspect You'll be happy - after the migration
As a start: Drag the exported data (-file) on the FileMaker icon. If the format is fine, FileMaker will create a vanilla db with Your data