The short answer....no. You are going to have to go thru the layouts, relationship graph, and scripts to figure it out. Doing a DDR will also help. Just make plenty of backups and testing so you can roll back if you get the DB too far out of whack.
If you are new to all things FM, and you need a really nice starter/intermediate Invoicing solution, you may want to check out this:
It's a full set of training videos & files that shows you how use FM & how to build an invoicing solution. You end up with great knowledge and skill & a really nice invoicing solution
Starting Point is a free open template, confusing coding standard to begin with.
Filemaker Naming Conventions.