Same here - in fact, I really could do with an overview of CRM concepts, particularly how they relate to SuiteCRM.
I’ve watched a couple of videos, but I still get the feeling I’m peering into little rooms rather than getting an overview of the whole office.
The user guide is comprehensive but again, doesn’t give an overview, and the forum is extremely quiet too, so questions like mine (and yours!) often go unanswered.
Could I to control my agreements just Proposals (with stage like won)?
Quote Stage = New, Assigned, Proposal, Closed Won, Closed Lost - Edit the dd to your stages
What different information exists between Proposals and Contracts?
These modules can be customised for your liking but current standard differences between the modules are within Contract information. E.g Renewal date, customer signed date, contract type.
Need I create a Invoice from Proposals or Contracts?
At the moment you can Convert Quote to Invoice
Convert Quote to Contract
With workflows and an admin process I am sure you can get invoices being created from a Contract relationship but is not standard
Is there a documentation that explain to concepts and goals aboud this modules?
I personally have not located any, my knowledge has been through trial & error experience!