Photoshop won't install

4gb is the minimum needed hd space, so double check that you have 6 gb (and you can assume you're going to have problems soon, even if you shoehorn photoshop onto your computer now).

first, reset the cc app:

to reset the cc desktop app, make sure it's in the foreground, then press:

Win: Ctrl + Alt + R
Mac: Cmd + Opt + R

if that fails, try to repair
https://helpx.adobe.com/download-install/kb/creative-cloud-install-stuck.html

if that fails go ahead and uninstall/reinstall per the above link

if that fails, do a clean cc install following each applicable step:

uninstall every cc app including preferences, https://helpx.adobe.com/creative-cloud/help/uninstall-remove-app.html
then uninstall the cc desktop app, https://helpx.adobe.com/creative-cloud/help/uninstall-creative-cloud-desktop-app.html
clean your computer of cc files per http://www.adobe.com/support/contact/cscleanertool.html
restart your computer (don't skip this)
reinstall the cc desktop app, https://creativecloud.adobe.com/apps/all/desktop?action=install&source=apps&productId=creative-cloud
if you're unable to install the cc desktop app at this stage, use the link at the bottom of the page at https://helpx.adobe.com/download-install/kb/creative-cloud-desktop-app-download.html
use the desktop app to install your cc programs/trials