I think I may have clicked on a link in an email via my 4s that's a phishing link.
However, safari failed to open the page, so will I be ok?
Very stupid of me I know!

If it was a link to something that would have required you to sign in, then you may be fine. If it's a link to a page that downloads a Windows executable, then again you should be fine because an exe file can't install on your phone.

If you clicked through from your email, or you did input a password for something, then change your email password or your login password just to be on the safe side.

If it's anything to do with banking or cards, check with your bank.

Thank you.
I clicked the link from my email which failed to open the page, I've changed my email password
I've also been advised to keep an eye now on my mobile data usage to see if that's a lot different to the norm