Cloud, 10.58 and Adobe Photoshop

Hi

This is my computer:

Model Name: iMac 10.58

Model Identifier: iMac8,1

Processor Name: Intel Core 2 Duo

Processor Speed: 3.06 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 6 MB

Memory: 4 GB

Bus Speed: 1.07 GHz

Boot ROM Version: IM81.00C1.B00

SMC Version (system): 1.30f1

Serial Number (system): YM83106K0KM

Hardware UUID: CC6CD7D1-1BB3-5D1C-BF9A-30D5DF5860B0

Sorry to ask a few questions- but they are all sort of interelated.

1. How do I increase the Ram? Best place to get it?

2. I have just purchased CLOUD as a student, but I only have a Mc OSX 10.58 and all the CS6, available Photoshop CS6 wont work. Adobe is not answering any questions, their forums are not responding..any ideas? Does that mean I have to get another whole new computer?

3. I have Adobe Masters CS5.5, have the seriel number etc, but have lost all the disks...:( One person from their Chat line who was on there for about a MINUTE said that I would have to buy another set if I can find one in Australia as they do not have a download for CS 5.5 anymore, regardless of the money you have paid....

HELP!

and I cant afford a new computer...and they won't answer my questions. I have CS5.5, with a seriel number and everything, but lost disks.