Hello,
SAP offers preparation for certification.
for FI associated levenl: TFIN50 and TFIN52 material is relevant.
I would also go through some additional AC material like:
AC 210 (New GL) or AC010 Overview FI
Anyway, just take a look on SAP training homepage, choose your course and have a look at the details, here the material is mentioned like AC*** and so on.
all the best Erwin