If you want more than just one model test, these publishers offer intensive "Prüfungstraining" books often available for purchase or found in libraries. Cornelsen - Prüfungstraining DaF: Goethe-Zertifikat A2
You can re-take individual modules at many Goethe-Institutes. However, if you fail the entire exam, you have to register again and pay the full exam fee. Check the rules at your local exam centre. goethe-zertifikat a2 prufungstraining pdf
This book is part of the "Mit Erfolg" series and is very popular among learners who want to go beyond simple practice tests. It offers: If you want more than just one model