Hi mamun22nd
Not sure who's doing your training. but below is a reply I posted to a similar question some time back. If you can't get your hand on the manuals, code7700 is a very good resource to start learning.
"Most of the FSI manuals are through their app now, you should get sent all the info prior to the course. If it hasn't arrived, just give them a call or email and they may send them to you early with login details for the app etc. If not, or if it's still too far away, try code7700.com. It's a guy who flies a G450 (fairly similar to 550). He's put together a pretty impressive website with all the systems and manual links as well as some other great stuff. To be honest, you'd probably pass a written test based on reading his website alone"
Hope that helps.
Enjoy the Gulfstream.