Hi friends, I have a problem. I have to learn sybase but I do not know where to start. Which tool I need? how I create a new data base?

Thanks for your help

You can start with the documentation that Sybase provides. Search on Sybase.com for the docs for the appropriate product you want to learn. There are quickstart-guides, installationguides, administrationguides, the lot.
But, it might be even beter to do a course with Sybase Learning, like a Fasttrack-course. Information about that is also available on the website.

Thanks, Could you say me how to restore backup? I have a backup but I don't know what type is it!. I use sybase central "restore" option but I got the message "Unable to open device"

There is a lot about backup and restore in the documentation, but the most basic course is loading a databasedump into the database you want to restore.
load database <dbname> from "<location>\<filename>"
This, providing you have a proper databasedump, should/could work. You can try load database <dbname> from "compress::<location>\<filename>" in case the dump was created using compression.