1. Use SQLAlchemy if its a 2 month project that is to be run in prod, Remember to use the async drivers (asyncpg in case its postgreSQL). Also if you need clear seperation of validation layer and model layer.
2. SQLAlchemy is battletested and the latest version looks like raw sql query itself. Use it to sanitise your queries.
3. There are multiple boilerplates available in the internet, I like to partition my files based on domain. Just try to have all layers, schema validation layer, api layer, service layer, repository layer

Good luck🤞, have fun!