Here are some answers to help clarify:
1. First, how can we join to your network?
Blockcerts isn’t a network, but rather a set of code libraries for issuing and verifying digital records. The goal is for these to operate as a standard to increase for using any documented blockchain.
2. Is it possible someones can bring to us support during the implementation of Blockcerts?
The code is fully documented, so any experienced developer should be able to use the libraries to build a system. There is no dedicated support, just volunteers of the community here.
3. What are the costs for issuing certificates?
This will depend on choice of blockchain. Issuing in batches is a mechanism that helps to keep costs down.
4. And, finally, this can be configurable by ourselves to create accounts? .
Blockcerts is simply code libraries. The system you create with them would have accounts.
LearningMachine.com is an example of a company that has used blockcerts to build a commercial product. I hope this helps!