I think to take beta OCA 1Z0-100. I worked several years with Linux, but my know how not up2date (6 years break). Are there any objectives or example questions? Is the exams comparable with OCA Solaris (the same simple?)?
Second question: will there be an official study guide for OCP Linux?
There is a list of exam topics on the website. Regarding an official study guide - Oracle Certification typically does not produce study guides. You can have a look at the Oracle Press site to see if they have anything on Linux 6. It is probably still too early to know if they will develop a study guide for this particular exam.