If it is your first time you see unix systems, I suggest to not install it because unix is completely different world then windows.
In regard on installation of solaris in machine with no cd-rom, there is plenty of possibilities e.g. JumpStart, liveUSB (if you have USB ports).
I would recommend you install via liveUSB method. Downolad iso image from sun.com and create liveUSB.
Here you have tutorial for liveUSB :
How to create and use Live USB - FedoraProject
If you already create liveUSB, you can install Solaris.
Here you have tutorial for installation of Solaris10
How to Install Solaris 10
In regard on subscription, up to couple months ago before sun joined oracle, policy was like this (now changed) :
- you can download solaris for free but patches not packages were payed
- in regard to have patches support, you had to regisdter your solaris on sun.com and pay for subscription
Patches (SunSolve) :
https://identity.sun.com/amserver/UI...do?target=home
Pakcages (SunFreeware) :
Sunfreeware - Free and Open Source Software (FOSS) for Sun Microsystem's Solaris
KnowHow (BigAdmin):
Oracle - BigAdmin System Administration Portal