I wish you success in achieving these goals. We’re here to help you along the way, so if you have any questions, you know where to find us.
Rene is in the process of updating the information on the forum concerning lab setups. In the meantime, you can take a look at the following two posts that will guide you in the right direction.
As for IOS versions, there’s no clear cut answer, as the exams don’t focus on particular versions of IOS. However, if you’re using 15.X IOS, then you’re just fine, regardless of the particular version.
As for studying, the following two posts will help you and will most likely answer most of your (excellent) questions:
If you need any further clarification, please feel free to let us know!