Remote logon has nothing to do with Cadence. It is an OS feature which can do in every nowaday OS both Unix, Linux and Windows, but, of course, Cadence doesn't run in Windows.
When you set up your own computer or receive a permission to remote logon to other server running Cadence, just invoke the software like you are in front that machine. That's all.
For the second question, if you think your future profession can effort Cadence then you should have its experience since now, otherwise learning Tanner software would be a greater choice since it is far more effortable.